• Preheat the oven to 325 degrees. Butter a 9-inch square metal baking pan and line with parchment, leaving a 2-inch overhang on 2 sides.
• In a large bowl, whisk together flour, baking powder, cinnamon, and salt and set to the side. Using a stand mixer, beat butter and 1 ½ cups brown sugar until fluffy. Add the vanilla and eggs; beat until combined. Reduce speed to low then add the flour mixture in 3 additions, alternating with 2 additions applesauce. Beat until combined.
• Transfer the batter to the greased pan and smooth top. Arrange apples in 3 rows on top of the batter, overlapping slightly. Bake until a toothpick inserted in center comes out with a few moist crumbs attached, 1 hour 15 minutes. Transfer pan to a wire rack and let cool 20 minutes.

Apple Cider Glaze:

• While the cake is cooling you will want to cook the apple cider and ¼ cup brown sugar in a medium sauce pan over medium-high heat. The cider should turn thick and syrup like after 15 to 18 minutes. Remove from the heat.
• Remove the cake from the pan using the pieces of parchment paper. Brush the cider glaze over top and sides of the cake. Let the cake rest an additional hour until set. Then slice and serve!