Classic Crumb Cake

Directions

1. 1
   Preheat the oven to 350F.
2. 2
   Generously butter a 13-by-9-inch baking pan; set aside.
3. 3
   Whisk together flour, baking soda, baking powder, and salt in a bowl; set aside.
4. 4
   In the bowl of an electric mixer fitted with the paddle attachment, beat the butter and sugar until light and fluffy, about 4 minutes, scraping down the sides of the bowl as needed.
5. 5
   Add the eggs, one at a time, beating until incorporated after each addition.
6. 6
   Mix in the vanilla.
7. 7
   Add the flour mixture and sour cream; beat just until combined.
8. 8
   Spoon the batter into the pan, and smooth with an offset spatula.
9. 9
   Sprinkle the topping evenly over the batter.
10. 10
    Bake, rotating the pan halfway through, until cake is golden brown and a cake tester inserted in the center comes out clean, 40 to 50 minutes.
11. 11
    Transfer to a wire rack to cool.
12. 12
    Before serving, dust with confectioners sugar, if using.