Sour Cream Coffee Cake

This recipe comes from the New York Times. Similar to our usual streusel coffee cake, but more moist.
NOTE: I made a half recipe and filled 5 ramekins (large muffin size). 

Ingredients

For the cake:
½ cup unsalted butter at room temperature
1 ¼ cups sugar
2 large eggs
1 ½ cups flour
1 ½ teaspoons baking powder
½ teaspoon baking soda
½ teaspoon salt
1 ¼ cups sour cream
1 teaspoon vanilla
For the topping:
½ cup sugar
2 teaspoons all-purpose flour
1 tablespoon cinnamon
⅓ cup chopped pecans or walnuts
NOTE: For the topping, I used my usual streusel (for a half recipe, I used 1 T butter, 1 T flour, 1/4 cup brown sugar and 1 t cinnamon).

Directions

1. Preheat oven to 350 degrees and generously butter a 9-by-13-inch baking pan. Cream butter and sugar together until light and fluffy. Add eggs one at a time, beating well after each addition.
2. In a separate bowl, sift flour with baking powder, baking soda and salt. With the mixer on low speed, add the flour mixture to the butter mixture alternately with sour cream and vanilla until just combined. Do not overmix. Pour batter into prepared baking pan.
3. Make the topping: Combine sugar, cinnamon, flour and nuts in a small bowl and mix well.
4. Sprinkle the topping evenly over the cake and bake 30 to 35 minutes, or until a cake tester comes out clean. Cool, cut into pieces and serve.