Preheat your oven to 350°F and line a cupcake pan with liners, enough for about 14 cupcakes.

In a mixing bowl, whisk together the flour, baking powder, and salt. Set aside.

In a stand mixer, cream the butter and sugar on medium-high speed for about 2 minutes until light and fluffy.

Add the eggs one at a time, followed by the vanilla extract, mixing on medium speed until combined.

Slowly beat in the sour cream until smooth.

Gradually add the dry mixture in batches, alternating with buttermilk, beginning and ending with the flour mixture.

Fill cupcake liners about two-thirds full and bake for 20-23 minutes, or until a toothpick inserted comes out clean. Let cool completely.

In a small saucepan over medium heat, add sugar ¼ cup at a time, stirring occasionally until each batch melts before adding more. Continue until all sugar is melted and turns a deep amber color.

Turn off the heat and add butter one piece at a time, stirring carefully as it may splatter. Add the heavy cream, salt, and vanilla extract, stirring until smooth. Set aside to cool until thick.

Using your stand mixer, beat the butter and powdered sugar on low speed until well blended. Increase the speed to high and whip for 2-3 minutes until fluffy. Add the vanilla extract, salt, and caramel, then mix again on medium speed for 2 minutes. If you prefer a creamier texture, add a tablespoon of heavy cream.

Using a large piping tip or a knife, cut out the center of each cooled cupcake. Fill each hole with caramel using a spoon. Pipe the buttercream on top of the cupcakes, then drizzle the remaining caramel over the frosting.