Ingredients
Method
Topping
- Mix both sugars, cinnamon, and salt in medium bowl and whisk to blend.
- Add warm melted butter and stir to blend.
- Add flour and toss with fork until moist clumps form. Set aside.
Cake
- Position rack in center of oven and preheat to 350°F.
- Butter 13x9x2-inch glass baking dish.
- Sift flour, baking soda, baking powder, and salt into medium bowl.
- Using electric mixer, beat room-temperature butter in large bowl until smooth.
- Add sugar and beat until light and fluffy, about 4-5 minutes.
- Add eggs 1 at a time, beating until well blended after each addition.
- Add sour cream and vanilla extract and beat just until blended.
- Add flour mixture in 3 additions, beating just until incorporated after each addition.
- Transfer cake batter to prepared baking dish; spread batter evenly with rubber spatula or offset spatula.
- Squeeze small handfuls of topping together to form small clumps. Drop topping clumps evenly over cake batter, covering completely.
- Bake cake until tester inserted into center comes out clean and topping is deep golden brown and slightly crisp, about 1 hour.
- Cool cake in dish on rack at least 30 minutes.
- Cut cake into squares and serve slightly warm or at room temperature.