Brown Butter Sour Cream Coffee Cake
2 cups (4 sticks) Crystal unsalted butter
1 1/4 cups all-purpose flour
1 cup (packed) dark brown sugar
1/4 teaspoon kosher salt
Crystal Unsalted butter (for pan)
2 3/4 cups all-purpose flour
1 tablespoon baking powder
1 teaspoon kosher salt
1 teaspoon ground cinnamon
3/4 teaspoon baking soda
1/2 teaspoon ground nutmeg
1 3/4 cups bakers sugar
4 large eggs
1 1/2 cups Crystal sour cream
1/2 cup Crystal whole milk
1 tablespoon vanilla extract
3/4 cup whole almonds, coarsely chopped
Simmer 2 cups butter in a large nonstick skillet over medium heat until browned bits form, about 6–8 minutes. Pour into a 2-cup measuring cup. If needed, add more butter to measure 1 3/4 cups (added butter will melt). Allow butter to cool for about 20-30 minutes but not solidify.
Whisk flour, sugar, and salt in a medium bowl. Stir in 3/4 cup brown butter (reserve remaining butter for cake); stir until moist clumps form. Set aside.
Preheat oven to 325°. Butter a 9×3 inch round springform pan generously. Whisk all-purpose flour and next 6 ingredients (through nutmeg) in a medium bowl. Using an electric mixer, beat remaining 1 cup browned butter and sugar in a large bowl until light and thick, 2–3 minutes. Add egg one at a time, beating to blend between additions. Beat in sour cream, milk, and vanilla. Stir in flour just to blend.
Spoon half of cake batter into prepared pan; smooth top. Scatter 1 cup of topping over. Spoon remaining batter in dollops over; smooth. Add almonds to remaining topping; squeeze to form 1/2” clumps and scatter evenly over batter in pan.
Bake until tester inserted into center of cake comes out clean, about 1 hour 20 minutes. Let cool in pan on a wire rack for 10 minutes. Run a knife around edge of pan to release cake. Remove pan sides; let cool completely.