01 - Preheat the oven to 350°F (175°C). Grease and flour a 9x13-inch baking pan.
02 - In a bowl, whisk together the flour, baking powder, baking soda, salt, and cinnamon. Set aside.
03 - In a large mixing bowl, cream together the softened butter, granulated sugar, and brown sugar until light and fluffy.
04 - Beat in the eggs one at a time, then stir in the vanilla extract.
05 - Gradually add the dry ingredients to the wet mixture, alternating with the buttermilk, and mix until just combined.
06 - Fold in the diced apples and chopped pecans.
07 - Pour the batter into the prepared baking pan and smooth the top.
08 - Bake for 45-50 minutes, or until a toothpick inserted into the center comes out clean.
09 - While the cake is baking, prepare the caramel glaze: In a saucepan, combine the brown sugar, butter, and heavy cream. Bring to a simmer over medium heat, stirring constantly until smooth. Remove from heat and stir in the vanilla extract.
10 - Once the cake is done, let it cool for 10 minutes before drizzling the caramel glaze over the warm cake.