In a medium saucepan, melt the unsalted butter over medium heat. Stir in the packed brown sugar until it's well blended and smooth. Remove from heat, and prepare for the next step!

Pour the luscious caramel mixture into the bottom of a 9-inch round cake pan. Make sure to coat the bottom evenly for a delightful caramel layer.

Neatly arrange the sliced apples over the caramel in a circular pattern. If you're feeling cozy, sprinkle ground cinnamon over the apples for an added spice note.

In a medium bowl, whisk together the all-purpose flour, baking powder, baking soda, and salt. Set this mix aside while you work on the wet ingredients.

In a large mixing bowl, beat the softened butter and granulated sugar together. Continue mixing until the mixture is light and fluffy, around 3–5 minutes.

Add the eggs one at a time to the buttery mix, making sure to mix well after each addition. Then, stir in the vanilla extract to enhance the delicious flavor.

Gradually add the dry ingredients to the wet mixture, alternating with the buttermilk. Mix until everything is just combined and smooth—no need to over-mix!

Carefully pour the cake batter over the beautifully arranged apples in the pan. Spread the batter evenly for a nice, even bake.

Place the cake in a preheated oven at 350°F (175°C) and bake for 40–45 minutes. A toothpick inserted into the center should come out clean when it's ready.

Allow the cake to cool in the pan for about 10 minutes. Run a knife around the edges to loosen it before inverting.

Carefully invert the cake onto a serving plate. Let it sit for a few moments, allowing the caramel to drizzle down the sides beautifully. Slice and serve warm or at room temperature; enjoy every bite!