Core and chop apples into no bigger than ½ inch pieces, place in a small bowl then set them aside. Then, in a large bowl whisk milk, egg, softened butter, brown sugar, unsweetened applesauce, and vanilla until well combined.
In a separate medium bowl, stir together the flour, salt, cinnamon, baking powder, and nutmeg. Add the dry ingredients to the wet ingredients and mix just until combined—be careful not to overmix. Gently fold in the apple chunks.
In a deep pot or Dutch oven, heat 2–3 inches of oil over medium heat to 350°F (175°C). Once the oil is hot, drop in ¼ cup scoops of the fritter batter. Gently flatten each scoop with the back of a spoon or a potato masher.
Fry for about 2 minutes on the first side, then flip and cook for another 2 minutes, or until golden brown and cooked through. Fry in small batches to maintain the oil temperature. Transfer the fritters to a wire rack or paper towels to drain.
While they’re still warm, whisk together the glaze ingredients until smooth. Drizzle over the fritters or dip them directly into the glaze. Place on parchment paper or a wire rack to set. These apple fritters are best enjoyed fresh and warm!