1. Prepare the pan

Preheat the oven to 350°F (175°C). Grease a mini bundt pan very well so the cakes release cleanly after baking.

2. Prepare the apples

Peel and finely dice the apples. Toss them with the lemon juice and set aside. This helps keep them fresh and bright.

3. Mix the dry ingredients

In a medium bowl, whisk together the flour, baking powder, baking soda, salt, cinnamon, and nutmeg.

4. Cream the butter and sugars

In a large mixing bowl, beat the softened butter, brown sugar, and granulated sugar until the mixture looks light and fluffy. This should take about 2 to 3 minutes.

5. Add the eggs and vanilla

Add the eggs one at a time, mixing well after each addition. Stir in the vanilla extract.

6. Add the sour cream and milk

Mix in the sour cream and milk until smooth. The batter may look slightly soft, and that is fine.

7. Combine wet and dry ingredients

Add the dry ingredients gradually to the wet mixture and stir until just combined. Do not overmix. Fold in the diced apples gently.

8. Fill the mini bundt pan

Spoon the batter into the prepared mini bundt pan, filling each cavity about 2/3 to 3/4 full.

9. Bake

Bake for 18 to 24 minutes, or until the tops are set and a toothpick inserted into the center comes out clean or with a few moist crumbs. Let the cakes rest in the pan for about 10 minutes, then carefully turn them out onto a wire rack.

10. Make the caramel apple topping

In a small saucepan over medium heat, melt the butter. Stir in the brown sugar, heavy cream, vanilla, salt, cinnamon, and diced apples. Cook for about 4 to 6 minutes, stirring often, until the apples soften slightly and the caramel becomes glossy and thick enough to spoon.

11. Finish the cakes

Spoon the warm caramel apple topping over each mini bundt cake. Let some of the caramel drip naturally down the sides for that bakery-style finish.