Step 1

Preheat the oven to 350ºF. Spray a 9x13-inch baking pan with cooking spray.

Step 2

In a large mixing bowl, stir together the flour, salt, cinnamon, sugars and vegetable oil. Mix until crumbly. Scoop out 1 1/2 cups of the crumbs and set them aside.

Step 3

To the remaining crumbs, add the beaten egg, 1/2 cup buttermilk, baking powder and baking soda. Mix for 2 minutes.

Step 4

Add the remaining 1/2 cup buttermilk and beat for an additional 2 minutes.

Step 5

Pour into the prepared pan. Sprinkle the reserved crumbs over the top. Sprinkle with additional cinnamon if you'd like.

Step 6

Bake for 38-40 minutes or until the center of the cake bounces back when you touch it. A toothpick inserted in the center should come out clean or with a few crumbs on it.

Step 7

Serve the cake warm.

Step 8

Store in an airtight container at room temperature.