Preheat the oven to 350°F (175°C). Lightly grease a baking dish.
In a large bowl, toss the thin apple slices with flour, brown sugar and nutmeg until they are evenly coated.
Either in a medium bowl using a hand mixer, or in a stand mixer with a whip attachment, cream together the egg replacer powder, and vegan butter until smooth.
Add the applesauce, sugar, lemon zest, lemon juice, cinnamon, and vanilla extract. Mix for about 60 seconds until well combined.
Sift in the flour, baking powder, and salt. Mix with a rubber spatula, or with the paddle attachment if using a stand mixer for 20-30 seconds, just until no dry spots remain.
Arrange most of the sliced apples in the prepared baking dish. Save 4-6 slices to place on top of the kugel.
Spread the batter evenly over the apples, smoothing the top with a wet offset spatula.
Top the kugel with a few reserved slices of seasoned apples.
Bake for 40-45 minutes, until the top is golden and a toothpick inserted in the center comes out clean.
Remove from the oven and while still warm, dust with cinnamon and dot with the thinly sliced pats of vegan butter, allowing it to melt over the surface.
If desired, dust with powdered sugar and serve with warm maple syrup on the side.