Combine the apples with the brown sugar, lemon juice, apple pie spice, vanilla, and salt. Bring to a boil, then lower to a simmer and let cook until the apples have softened (about 10 minutes). Then remove the apples and let the liquid reduce until it coats the back of a spoon (another few minutes, but watch it!).Once the liquid has reduced, pour it back over the apples and mix. Let cool. Preheat the oven to 350 degrees F and line a bread pan with parchment paper. Set aside.
Combine the dry ingredients (flour, baking powder, apple pie spice, and salt) in a bowl and set aside.
Add the butter and sugar to a stand mixer fitted with the paddle attachment. Start on low, then increase to medium-high, and mix for about 3 minutes, or until fluffy. Add the eggs and vanilla and mix until combined.
With the mixer on low, add the dry ingredients to the wet ingredients. Once incorporated, slowly add the milk and mix until just combined.
Add ⅔ of the apple pie filling to the batter and fold in. Pour the batter into the bread pan. Add the rest of the apple on top, then sprinkle brown sugar and a little salt on the top.
Bake in the preheated oven for 50-55 minutes, or until the center is set. Let sit in the pan until mainly cooled, then remove.
Make the glaze, and drizzle over the bread.