**Preheat Oven:**
Preheat your oven to 350°F (175°C) and grease a 9x13-inch baking dish or bundt pan.
**Mix Dry Ingredients:**
In a medium bowl, whisk together flour, baking powder, baking soda, cinnamon, nutmeg, and salt.
**Cream Butter and Sugars:**
In a large bowl, beat the softened butter, granulated sugar, and brown sugar until light and fluffy.
**Add Eggs and Vanilla:**
Beat in eggs one at a time, then add vanilla extract and mix until combined.
**Incorporate Sour Cream and Dry Ingredients:**
Mix in the sour cream, then gradually add the dry ingredients, mixing until just combined.
**Add Apples and Pecans:**
Fold in the diced apples and chopped pecans.
**Bake:**
Pour the batter into the prepared pan and smooth the top. Bake for 40-45 minutes, or until a toothpick inserted in the center comes out clean.
**Make the Caramel Glaze:**
In a saucepan over medium heat, melt the butter. Stir in the brown sugar and heavy cream, cooking until the mixture bubbles and thickens slightly. Remove from heat and stir in vanilla extract.
**Glaze the Cake:**
Once the cake has cooled slightly, pour the warm caramel glaze over the top. Let it set before serving.