Heat both portions of butter (14 tbsp) in a large light-colored sauté pan over medium high heat, stirring often.
14 tbsp salted butter
Watch carefully as it begins to foam and the milk solids separate, and once the milk solids begin to turn a deep golden brown and the butter has a nutty aroma, remove from heat to a heat-safe container, scraping all the brown bits with it.
Stir brown butter well and remove ½ cup of it for frosting. You should have one container with 6 tablespoons and one with ½ cup.
Place both containers in the refrigerator to chill for one hour, then allow to come to room temperature.
Brown Butter Pecan Cake Layers
Preheat oven to 350°F and position oven rack in middle of oven. Spray 6-inch cake pans with baking spray and line with parchment paper.
In a medium bowl, whisk together cake flour, baking powder, and baking soda until well combined.
1 cup cake flour, ¾ tsp baking powder, ¼ tsp baking soda
Fold in toasted chopped pecans and mix well. Set aside.
1 cup pecan halves
Cream 6-tbsp. portion of brown butter with brown sugar and granulated sugar with an electric mixer until light and fluffy.
14 tbsp salted butter, ⅓ cup brown sugar, ⅓ cup granulated sugar
Beat in eggs and vanilla and continue to mix for 2-3 minutes. Mix in sour cream.
2 large eggs, 2 tsp pure vanilla extract, 1/2 cup sour cream
Fold in flour/pecan mixture gradually until just combined.
Divide cake batter evenly into prepared cake pans (I use a food scale for this step) and bake 20 minutes, or until a toothpick entered into the center of each layer comes out clean.
Let layers cool in pans for 15 minutes, then turn out onto wire racks to cool completely.
Brown Butter Cream Cheese Frosting
Whip remaining ½ cup of brown butter with an electric mixer until lightened in color. Add cream cheese and beat until smooth. Mix in vanilla.
8 oz cream cheese, 1 ½ tsp pure vanilla extract, ½ cup brown butter
Gradually sift in powdered sugar, mixing well.
4 cups powdered sugar
Beat another 2 minutes until frosting is light and fluffy. Spread onto cooled cake layers.
Storage/freezing: You can store your frosted butter pecan cake at room temperature, covered with a large bowl or cake holder, for up to 3 days. It can also be frozen, well wrapped in an airtight container, for up to 2 months.Cake flour substitute: You can make a cake flour substitute using all-purpose flour and cornstarch! Just sift together 14 tablespoons (109g) of all-purpose flour and 2 tablespoons (16g) of cornstarch. Then add it in with your dry ingredients as usual!Toasting pecans: You can do this step in advance, but I like to toast my pecans in the pan where I just browned my butter. That way my pecans can soak up some of that remaining buttery goodness! Simply toss your pecan halves in a pan (buttered or dry) and heat them over medium head for about 10-15 minutes, stirring often. They should begin to smell amazing and get nicely browned. Just be careful to watch them so that they don't burn. Once they're toasted, let them cool and then chop them for your batter!