Make the crust: In a large bowl, combine the spelt flour, salt, and sugar. Add the buttery spread and mix using a pastry cutter.
Add the cold water a little bit at a time and mix until the dough just comes together.
Flatten the dough into a disk and wrap with plastic wrap. Place dough in the freezer for one hour.
Preheat the oven to 350 degrees.
Line a surface with wax paper and sprinkle flour on top. Flour the rolling pin as well. Roll out the dough into a 16 inch circle if you are using a 12 inch tart pan. You can adjust the size of your dough to fit the pan you have.
Put the dough into the tart pan and press it into the sides, removing any excess. Prick the bottom all over with a fork, then bake at 350 degrees for 15 minutes.
While the tart bakes, combine the Ambrosia apples with the cinnamon, ginger, and sugar and set aside.
In a large bowl, place the flour, oats, brown sugar, salt, and cinnamon and mix together. Add the vegan buttery spread and mix using a pastry cutter until the mixture becomes a crumb topping.
Remove the crust from the oven and fill with the apples and then place the crumble on top.
Bake the tart at 350 degrees for about 40 minutes.
Let cool before serving.