Add some vanilla ice cream to this dessert to take it over the top!
Preheat oven 350F. Prepare 9 inch cake pan with parchment paper and non-stick spray. In a small bowl, mix butter, sugar, and cinnamon until smooth. Spread on bottom of prepared of pan. Arrange slices of apples in a pretty presentation onto of butter mixture, set aside.
In a medium bowl, whisk dry ingredients and set aside.
In a large bowl, beat butter and sugar until smooth and fluffy. Add eggs, one at a time mixing well after each. Add vanilla and stir until combined. Alternate dry ingredients and buttermilk into wet ingredients blending after each addition. End with flour.
Pour batter carefully over apple mixture. Bake for 35-40 minutes until toothpick comes out clean. Cool in pan for ten minutes, take a knife around the edge and flip gently onto a serving platter. Serve warm or at room temperature.