In a 9 or 10-inch heavy bottom skillet* combine the butter, apple juice, maple syrup and vanilla. Bring to a simmer over medium heat.

Arrange the apples in one layer in the skillet. They can overlap a little since they'll shrink. Fill in the empty spots too. Cook stirring occasionally over medium heat until most of the liquid reduces and the apples are soft, about 10 minutes. Remove from heat.

Preheat oven to 400 degrees.

In a large mixing bowl, combine the almond flour, arrowroot, maple syrup, baking powder, and salt with a wooden spoon and slowly add the water to form a ball of dough.

Place the dough on a piece of unbleached parchment paper or plastic wrap and flatten out with your hands or the bottom of a measuring cup to make a 9-inch circle. Or roll with a rolling pin in between two pieces of parchment/plastic. It is best if your crust is one inch smaller than the size of your skillet. If using a 9-inch skillet, make an 8-inch disc.

Arrange the apples on the skillet with the rounded side down. Place the crust on top and press lightly.

Bake for 35-40 minutes or until crust is golden and firm.

Remove from oven and cool for 15-20 minutes before carefully inverting onto a plate.