Instructions

1. In a bowl, add the Flour, Sugar,  Baking Powder and Salt and mix until combined.
2. In a second bowl, whisk together the eggs, buttermilk, melted butter and vanilla.
3. Pour the wet ingredients into the bowl with the dry ingredients.  Stir with a spoon (do not use mixer) until the batter is just combined.
4. Spread batter into a greased 9-inch square baking pan.
5. In a small bowl, mix the white sugar and cinnamon.
6. Spoon the cinnamon sugar onto cake and use a knife to swirl into the batter.
7. In a medium bowl, combine 1/4 cup cubed butter, brown sugar, flour, salt and cinnamon.  Use a fork, pastry blender or your fingers to mix until combined.
8. Sprinkle the brown sugar/butter topping over the top of the cake.
9. Bake in an oven preheated to 350 degrees for 30-33 minutes.
10. Serve warm.