Sour Cream Coffee Cake

Cake:
12 tbsp. unsalted butter, at room temperature
1 1/2 c. sugar
3 eggs, at room temperature
1 1/2 tsp. vanilla extract
1 1/4 c. sour cream
2 1/2 c. cake flour
2 tsp. baking powder
1/2 tsp. baking soda
1/2 tsp. salt

Streusel:
1/4 c. light brown sugar, packed
1/2 c. all-purpose flour
1 1/2 tsp. ground cinnamon
1/4 tsp. salt
3 to 4 tbsp. cold unsalted butter, cut into pieces
3/4 c. chopped walnuts, optional

Maple Glaze:
1/2 c. confectioners’ sugar
2 tbsp. real maple syrup

Preheat the oven to 350°F. Grease and flour a 10-inch tube pan.

Cream the butter sugar in the bowl of an electric mixer fitted with paddle attachment on medium-high speed for 4 to 5 minutes, until light and fluffy. Beat in eggs one at a time, then add vanilla and sour cream, scraping down bowl between additions. In a separate bowl, sift together flour, baking powder, baking soda, and salt. With the mixer on low, add flour mixture to batter until just combined.

To make streusel, place brown sugar, flour, cinnamon, and salt in a bowl and mix together with a fork. Add butter and pinch together with your fingers until it forms a crumble. Mix in walnuts, if desired.

Spoon half of the batter into prepared pan and spread it out with a knife. Sprinkle with 3/4 c. streusel mixture. Spoon the rest of the batter into the pan, spread it out, and sprinkle with remaining streusel. Bake for 50 to 60 minutes, or until a toothpick inserted in the center comes out clean.

Let cool on a wire rack for at least 30 minutes. Carefully transfer cake, streusel side up, onto a serving plate. Whisk together confectioners’ sugar and maple syrup, adding a few drops of water if necessary to make it runny. Drizzle as much glaze as you'd like over the cake with the whisk, a fork, or a spoon.