This brown butter cinnamon coffee cake is everything a coffee cake should be: soft, moist, and deeply cozy.
Brown the Butter Once
There is brown butter in the batter, streusel, and glaze. You can brown the butter separately for each layer, or brown it all at once and divide it after.
To do this, start with 1 cup (226g) unsalted butter total for the entire recipe.
Divide the browned butter:
- 50% for the batter
- 38% for the streusel
- 12% for the glaze
Streusel
Make the streusel first so it can chill while you prepare the cake.
- In a bowl, combine the streusel portion of brown butter with both sugars, cinnamon, salt, and vanilla.
- Stir in flour until both small and large buttery clumps form.
- Chill in the refrigerator while making the batter.
Cake
- Preheat oven to 350°F (175°C). Line an 8×8-inch pan with parchment.
- Whisk flour, baking powder, baking soda, salt, and cinnamon. Set aside.
- In another bowl, whisk the cooled brown butter with both sugars.
- Add eggs one at a time, then vanilla.
- Whisk in sour cream and milk.
- Fold in dry ingredients just until combined.
- Spread half the batter into the prepared pan.
- Sprinkle with half the streusel.
- Spoon remaining batter gently over the top.
- Finish with remaining streusel.
- Bake 40–45 minutes, until a toothpick shows moist crumbs.
- Cool 30 minutes.
Glaze
While the cake is baking, whisk glaze ingredients until smooth. Drizzle over the warm cake.
- Place the butter in a light-colored saucepan over medium heat.
- Let the butter melt completely, then continue cooking as it begins to foam and bubble.
- Swirl the pan occasionally to help the butter cook evenly and prevent the milk solids from sticking to the bottom of the pan.
- Watch closely for golden brown bits forming at the bottom. The butter will go through a loud bubbling stage while the water cooks off.
- As the bubbling sound begins to quiet down, the butter will start smelling deeply nutty and toasted while turning a rich amber color.
- Remove from the heat immediately and pour the brown butter into a mixing bowl to stop the cooking process and prevent burning.
You want golden, not burnt. Think toasted hazelnut, not coffee ash.
Storage
- Room temperature: 2 days, covered
- Refrigerator: Up to 5 days
- Freeze: Wrap slices tightly and freeze up to 2 months
Warm slices briefly before serving for best texture.