4 sticks of unsalted butter

Melt butter in a large stainless steel (or light colored) sauce pan over low to medium heat. As the water cooks out, the butter will sizzle a lot. Stir frequently with a silicone spatula.

Once the butter starts to foam, usually about 5 minutes in, you want to watch it very carefully so it doesn’t burn. You’ll also want to use your spatula to scrape the sides and bottom of the pan often. This will promote even browning and help prevent the milk solids from sticking to the pan as they brown. They’re delicious so you want them in your finished butter, and if they do stick they’ll be a pain in the butt to clean.

The foam may make it hard to see, but as you stir you’ll begin to see the milk solids in the butter begin to turn brown. Once the milk solids are brown and the butter smells toasty and nutty, you’re done! Immediately pour the butter, milk solids & all, into a heatproof dish to prevent it from further cooking. The milk solids can go from nutty and golden to black and burnt in less than a minute!

For the recipes below, you want the butter to be soft, but you don’t want to use the butter while it’s still hot and melted. Refrigerate the butter until solid, then let it soften at room temperature. If you want to make it ahead, it’ll keep for a long time if stored in an airtight container.
Butter contains a good amount of water which cooks off when you brown it, so after browning your 4 sticks of butter won’t measure 2 cups. Since the cake and the icing require the same amount of butter, I just say 1/2 the brown butter in each recipe for simplicities sake.

Brown Butter Pecan Cake
Adapted from Cooking Classy

3 Tbsp unsalted butter
2 cups finely chopped pecans
1/3 cup whole pecan pieces for decorating (optional)
3 cups all-purpose flour
2 tsp baking powder
1/2 tsp baking soda
1 tsp salt
1/2 of the brown butter (will be a bit shy of 1 cup), softened
1/4 cup peanut oil (or canola or vegetable oil)
1 cup granulated sugar
1 cup brown sugar, firmly packed
3 large eggs
2 large egg yolks (reserve whites for icing)
2 tsp vanilla extract
1 1/4 cup buttermilk

Preheat oven to 350 degrees.

Melt 3 Tbsp butter in a skillet over medium heat. Add pecans, toss to coat, and cook until slightly browned and fragrant, stirring frequently, about 5 minutes. Transfer to a bowl or dish to stop cooking and set aside to cool. If using whole pieces for decorating, separate them from the chopped pecans and reserve for later.

Butter 3 8-inch round cake pans and line with parchment paper, butter parchment paper and then lightly dust pans with flour shaking out excess. Set pans aside.
Whisk together flour, baking powder, baking soda and salt in a medium bowl and set aside.
In the bowl of an electric stand mixer fitted with the paddle attachment, beat butter, oil, and sugars together until very pale and fluffy, about 5 minutes. Mix in eggs and egg yolks, one at a time, adding in vanilla with the last egg.
Add 1/3 of the flour mixture to the butter mixture and mix on low speed just until combined, then add in 1/2 of the buttermilk and mix just until combined. Repeat alternating flour and buttermilk, ending with the final 1/3 of the flour. Remove the bowl from your mixer and fold in pecans until they’re evenly distributed. Divide batter evenly among the 3 prepared baking pans, using a kitchen scale for accuracy if desired.
Bake in preheated oven 25 – 30 minutes, or until a cake tester or toothpick inserted into the center of the cakes comes out clean.
Remove from oven and cool for 10 to 15 minutes on a wire rack, then run a knife around edges of the pans to ensure the cakes are loosened, and invert them onto the racks to cool completely.

Bourbon Caramel Sauce
Adapted from Minimalist Baker

1 cup sugar
1/4 cup water
1/4 cup unsalted butter (4 tablespoons, or 1/2 stick)
1/4 cup heavy cream
1 Tbsp bourbon (optional)
pinch of salt

Place sugar and water in a large saucepan over medium heat, gently swirling the pan (not stirring) to combine. Simmer (not stirring) for about 15 minutes or until a rich amber color is reached. It should look almost a reddish-brown, and have a slightly toasty aroma. Once the sugar starts to go from clear to golden, watch it very closely as it can go from perfect to burnt in under a minute. If you want to use a thermometer, cook until the sugar reaches 350 degrees.
Remove the pan from heat and slowly stir or whisk in the butter. It will bubble up a lot so be careful. Once the butter is combined, repeat the process with the cream. Then add the bourbon and salt stir or whisk to combine.
Place the pan back over the heat and simmer for another minute or two while stirring continuously.
Remove from heat and let it cool for about 15 minutes before pouring into a heat-safe dish or jar to cool to the touch. Then close or cover the container and transfer it to the refrigerator to cool completely before use. Any leftover caramel (I didn’t have much) can be stored in the fridge in an airtight container for several weeks.

Brown Butter Swiss Meringue Buttercream
Adapted from Martha Stewart 

6 large egg whites
1 cup granulated sugar
1 cup packed dark-brown sugar
1/2 teaspoon salt
2 sticks (1 cup) unsalted butter, room temperature
remaining 1/2 of the brown butter (will be a bit shy of 1 cup), softened
1 teaspoon vanilla extract

Wipe the bowl of an electric mixer with paper towel and a small amount lemon juice or vinegar to remove any trace of fat or grease. Make a double boiler by placing the mixer bowl over a saucepan of gently simmering water, making sure the bowl doesn’t touch the water.

Place egg whites, sugars, and salt into the bowl and whisk gently but continuously until the sugar is completely dissolved and the egg whites reach between 150 and 160 degrees F.
Attach the bowl to your mixer and use the whisk attachment to whip the egg whites on high speed until thick, glossy peaks form and the bowl no longer feels warm to the touch, about 7 to 10 minutes.
Switch to the paddle attachment and reduce speed to medium-low. Add butter, about 2 tablespoons at a time, beating after each addition. The meringue will deflate slightly as butter is added, don’t worry. Once all the butter is added, beat until the icing is smooth and silky, usually about 3 to 5 minutes.
Add the vanilla and beat on low just until combined.

If the buttercream curdles, don’t worry! Just keep mixing and it will come back to smooth.
If the buttercream is too thin and runny, refrigerate the bowl for about 15 or 20 minutes before mixing again with the paddle attachment until it comes together.

Assemble cake:

Remove parchment from each layer, and trim the domed tops off with a cake leveler or sharp bread knife if necessary. Flat layers will definitely result in a much prettier & more professional looking finished cake. My cakes didn’t dome much, so you may not need to do this step. Make sure the layers are completely cool (or cold) before you proceed.

If you’re not serving the cake the same day it’s baked, I recommend you brush each layer of cake with two or three tablespoons of simple syrup before assembly to keep it nice and moist for days. Just heat 1/3 cup sugar and 1/3 cup water together until the sugar is completely dissolved.

Place first layer on a cake stand, serving platter, or cardboard cake round. Top with roughly 1/4 of your icing (about one generous cup), and spread the icing out with an offset icing spatula, in as even and level a layer as possible. Place the next layer on top and check from above and from multiple angles to make sure it’s stacked perfectly centered with the layer below, and that it’s flat and level. Adjust if necessary.
Add another 1/4 of the icing, smooth it out, add the top layer, and check and adjust if necessary.

Using another 1/4 of your icing, spread a thin layer of icing over top and sides of cake with an icing spatula. I like to start at the top and slowly work my way down the sides. Be sure to fill in any gaps between layers and make the sides and top is as smooth and flat as possible. This thin layer of icing is referred to as the “crumb coat” and is meant to seal in any crumbs so they’re not seen in your final layer of icing. Refrigerate the cake for 30 minutes to an hour to set the icing before you proceed.
Spread the remaining icing evenly over top and sides of cake, trying to get as smooth a surface as possible.

Top the cake with about 3/4 to 1 cup of the cooled caramel sauce, carefully and evenly drizzling some down the sides.
If desired, top the finished cake with the optional 1/3 cup of toasted whole pecans from above.

This cake is best the day it’s baked, but will keep well in a cake saver at room temperature for up to 2 days, if the weather is not too hot or humid. Otherwise, wrap tightly and store in the refrigerator for up to 3 days. If refrigerated, you’ll need to let it come up to room temperature for at least an hour before serving.