- Preheat oven to 350 degrees and brush melted butter over insides and bottoms of heart shaped cupcake pan.
- Distribute the rest of the melted butter in the bottoms of the cupcake pan and sprinkle brown sugar over the melted butter, distributing evenly.
- Arrange peach slices on top.
- Beat together eggs, 2 tablespoons buttermilk and vanilla.
- Combine flour, sugar, baking powder, baking soda and salt (dry ingredients).
- Whisk together 6 tablespoons softened butter and 6 tablespoons buttermilk (wet ingredients).
- Add 1/4 of the dry ingredients to egg mixture and beat to combine.
- Beat in 1/4 of the wet ingredients and beat to combine, then continue adding dry and wet ingredients alternately, beating after each addition until well mixed.
- Scoop batter atop sliced peaches, being careful not to over fill.
- Bake for about 20 minutes in preheated oven until toothpick inserted in center comes out clean. Let cool 2-3 minutes, then invert and transfer Saturn Peach Upside Down Cakes to serving plates.
Serve warm with piped sweetened whipped cream and thinly sliced Saturn peaches.