Preheat the Oven: Preheat your oven to 350°F (175°C). Grease a 9-inch round cake pan and line the bottom with parchment paper.
Cream the Butter and Sugar: In a mixing bowl, cream together the softened butter and sugar with an electric mixer until light and fluffy (about 2-3 minutes).
Add Eggs and Vanilla: Add the eggs one at a time, beating well after each addition. Stir in the vanilla extract.
Combine Dry Ingredients: In a separate bowl, whisk together the flour, baking powder, and salt. Gradually add this dry mixture to the butter mixture, alternating with the buttermilk.
Mix in Heavy Cream: Stir in the heavy cream until the batter is smooth.
Bake: Pour the batter into the prepared cake pan and spread it out evenly. Bake for 30-35 minutes or until a toothpick inserted into the center comes out clean.
Cool and Serve: Allow the cake to cool for 10 minutes before transferring it to a wire rack to cool completely. Serve with whipped cream, ice cream, or fresh berries if desired.