The Best Crumb Cake This was amazing and will now be my go-to cake! Try this one soon! The Best Crumb Cake Ingredients Cake 2 and 1/2 cups flour 1 teaspoon baking soda 1/2 teaspoon baking powder 1/2 teaspoon salt 3/4c. room temp butter 1c. sugar 3 eggs 1 cup sour cream 2 tsp. vanilla