1-First Step: Mise en place and brown the butter. Start by measuring 1 1/4 cups unsalted butter into a light-colored saucepan. Place over medium heat, stirring occasionally. It will melt, foam, and then develop golden bits at the bottom after 5-7 minutes. Smell for a nutty aroma, then remove from heat immediately. Strain through cheesecloth into a bowl to remove solids. Let cool to room temperature; you’ll have about 1 cup browned butter. Reserve 1/2 cup cold, cubed for the topping. This step builds the cake’s signature flavor.

2-Second Step: Prepare the batter. In a large bowl, whisk together 2 cups flour, 1 cup granulated sugar, 1 tsp baking powder, 1/2 tsp baking soda, and 1/2 tsp salt. In another bowl, beat 2 eggs, then mix in 1 cup sour cream, 1/2 cup maple syrup, 1 tsp vanilla, and 1/2 cup (room temp) brown butter until smooth. Gently fold wet into dry ingredients until just combined; avoid overmixing for tenderness. Spread batter evenly into the prepared pan.

3-Third Step: Make the streusel topping. In a medium bowl, combine 1 cup light brown sugar, 1 cup flour, and 1 tsp cinnamon. Add 1/2 cup cold cubed brown butter. Use a fork or pastry cutter to mix until pebbly and crumbly, like wet sand. Do not overwork it. Chill the mixture for 15 minutes in the fridge for better texture.

4-Fourth Step: Assemble and bake halfway. Sprinkle the chilled streusel generously over the batter. Bake at 350°F for 20-25 minutes. This prevents the topping from sinking.

5-Fifth Step: Finish baking. Continue baking another 25-30 minutes, until the edges pull away from the pan and a toothpick inserted in the center comes out clean (total 45-55 minutes). Rotate the pan halfway for even browning. The crumbs should turn golden and crisp.

6-Final Step: Cool and serve. Let the cake cool completely in the pan on a wire rack, about 2 hours. This sets the crumbs. Slice into 12-16 pieces. Dust with powdered sugar or drizzle with extra maple syrup for shine. Pair it with coffee for brunch or ice cream for dessert. Store as noted below.