Preheat oven to 350° and line a 11x8 pan with foil and grease.

In a large bowl, combine flour, butter, sugar, and salt until fully combined. It will be crumbly. Measure out one cup and set aside for the topping.

To the remaining batter, add egg, buttermilk, baking soda, baking powder, and vanilla.

Pour into pan and smooth to make sure it's even.

In a small bowl, beat the cream cheese and sugar together until combined and smooth.

Add the egg and vanilla and mix until fully incorporated.

Pour on top of the cake layer.

Top with blueberries and sprinkle the remaining flour mixture on top for the crumb.

Bake for 45-55 minutes or until the center is no longer jiggly. Sometimes the toothpick test doesn't work because it will pick up the cream cheese.

Cool completely before glazing.