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.
Add the butter and salt to a stand mixer fitted with the paddle attachment. Start on low, then increase to medium-high and let mix for about 3 minutes or until fluffy. Add the eggs and vanilla and mix until combined.
Combine the flour, baking powder, apple pie spice, and salt in a bowl. Pour into the wet ingredients. Start on low and increase to medium. Slowly add the milk and mix until just combined. Finish mixing with a rubber spatula.
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.