*To make homemade cake/pastry flour for every cup of all purpose flour remove 2 tablespoons and replace with 2 tablespoons of cornstarch. Sift together to remove any lumps.
**If using unsalted butter then add 1/4 teaspoon of salt
For room temperature remove ingredients from the fridge about 30-45 minutes before using.
Pre-heat oven to 350°. Lightly grease and flour an 8 inch spring form cake pan or regular cake pan.
CRUMB TOPPING
In a medium bowl whisk together sugars, salt and cocoa add warm melted butter and stir to combine, add flour and mix with a fork until moist clumps appear, set aside.
FOR THE VANILLA CAKE
In a large bowl whisk together flour, baking soda, baking powder and salt.
In a medium bowl beat butter until smooth & creamy then add the sugar and continue to beat until light and fluffy, continue beating while adding egg and yolk, (one at a time), then add the yogurt, milk and vanilla, add the flour mixture a third at a time beating just until mixed. Spread in prepared pan and cover cake batter with crumb topping, do not press down. Bake approximately 1 hour. Let cool. Enjoy!
Notes
Leftover cake should be covered with plastic wrap and stored at room temperature. It will keep for three to four days.You can also freeze this cake. Once it’s completely cooled, Wrap it tightly in plastic wrap and store it in a freezer container. It will keep for three months.