Classic Coffee Cake - cooking recipe

Ingredients

Topping
1/2 cup firmly packed light brown sugar
2/3 cup all-purpose flour
1/2 teaspoon ground cinnamon
salt, pinch
1/4 cup cold unsalted butter, cut up
Cake
2 tablespoons white vinegar, plus enough milk to equal 1 cup (or use 1 cup buttermilk)
2 cups all-purpose flour
1 1/2 teaspoons baking powder
1/2 teaspoon baking soda
1/4 teaspoon salt
6 tablespoons butter, softened
2/3 cup firmly packed light brown sugar
1 teaspoon vanilla extract
2 large eggs
2 teaspoons confectioners' sugar

Preparation

Heat oven to 350 degrees F; coat 9-inch square baking pan with cooking spray.
For topping, in medium bowl, blend brown sugar, flour, cinnamon and salt.
With pastry blender, cut butter into flour mixture until crumbs form; chill.
For cake, (if not using buttermilk) pour vinegar into a measuring cup; add enough milk to equal 1 cup.
Set aside.
In medium bow, whisk together flour, baking powder, baking soda and salt.
In large bowl, beat butter, sugar and vanilla until fluffy, 2 minutes.
Add eggs, one at a time, beating well after each.
Working in batches, beat in milk mixture alternately with flour mixture.
Scrape batter into pan.
Sprinkle with topping.
Bake at 350 degrees for 1 hour, until a toothpick inserted into cake comes out clean.
Cool in pan on wire rack.
Dust with confectioners' sugar; cut in squares.
If you don't own a powdered sugar sifter, use a wire-mesh container or strainger to dust top of cake.