Remove from heat and let cool slightly.
In a bowl, mix oats, brown sugar, cinnamon, and nutmeg. Cut in cold butter until the mixture resembles coarse crumbs. Set aside.
Preheat the oven to 350°F. Grease and flour a 9x13-inch pan.
In a large bowl, whisk together sugars and brown butter until combined.
Add eggs one at a time, beating well after each addition. Stir in vanilla extract and orange extract.
In a separate bowl, whisk together flour, baking powder, baking soda, salt, and cinnamon.
Gradually add the dry ingredients to the wet ingredients and mix until just combined.
Fold in chopped apples and pecans.
Pour batter into the prepared pan and spread evenly.
Sprinkle the spiced crumble topping evenly over the batter.
Bake for 45–55 minutes or until a toothpick inserted in the center comes out clean.
Let the cake cool completely before drizzling with the caramel glaze.
While the cake is cooling, prepare the glaze. In a small saucepan, melt the butter over low
heat.Stir in the brown sugar and milk, and bring the mixture to a boil over low heat. Once boiling, reduce to a simmer and continue to stir constantly.
Allow the mixture to boil for 10 minutes until it thickens slightly, then remove from heat.
Stir in the vanilla extract and let the glaze cool slightly; it should still be pourable but not too hot.
Drizzle over the cake.