Sour Cream Coffee Cake*

12 tablespoons (1 1/2 sticks) unsalted butter at room temperature

1 1/2 cups granulated sugar

3 extra-large eggs at room temperature

1 1/2 teaspoons pure vanilla extract

1 1/4 cups sour cream

2 1/2 cups cake flour (not self-rising)

2 teaspoons baking powder

1/2 teaspoon baking soda

1/2 teaspoon kosher salt

1/4 cup light brown sugar, packed

1/2 cup all-purpose flour

1 1/2 teaspoons ground cinnamon

1/4 teaspoon kosher salt

3 tablespoons cold unsalted butter, cut into pieces

3/4 cup chopped walnuts, optional

1/2 cup confectioners’ sugar

2 tablespoons real maple syrup

Preheat the oven to 350 degrees F. Grease and flour a 10-inch tube pan.
Cream the butter and sugar in the bowl of an electric mixer fitted with the paddle attachment for 4 to 5 minutes, until light.
Add the eggs 1 at a time, then add the vanilla and sour cream.
In a separate bowl, sift together the flour, baking powder, baking soda, and salt.
With the mixer on low, add the flour mixture to the batter until just combined.
Finish stirring with a spatula to be sure the batter is completely mixed.
For the streusel, place the brown sugar, flour, cinnamon, salt, and butter in a bowl and pinch together with your fingers until it forms a crumble. Mix in the walnuts, if desired.
Spoon half the batter into the pan and spread it out with a knife.
Sprinkle with 3/4 cup streusel.
Spoon the rest of the batter in the pan, spread it out, and scatter the remaining streusel on top.
Bake for 50 to 60 minutes, until a cake tester comes out clean.
Let cool on a wire rack for at least 30 minutes.
Carefully transfer the cake, streusel side up, onto a serving plate.
Whisk the confectioners’ sugar and maple syrup together, adding a few drops of water if necessary, to make the glaze runny.
Drizzle as much as you like over the cake with a fork or spoon.