Start by preheating your oven to 350 degrees and grease an 8x8 baking dish and set it aside.
Get a large mixing bowl and add your dry ingredients; flour, sugars, rolled oats, brown sugar, baking soda, and baking powder, and whisk until well combined. Now add your melted vegan butter and stir until combined.
If you haven't done so yet, peel and remove the seeds of your apples, then cut them very thin. Take a medium bowl and combine your apple ingredients; apple slices, white sugar, flour, cinnamon, nutmeg, and salt, and stir until combined well.
Add your apple mixture to the prepared pan and then crumble the crust over the top of the apples.
Bake in the preheated oven for 30 minutes; check with a toothpick if the apples are still crunchy, put foil over the crisp and bake for additional 5 minutes, and check again.
Let cool on the counter to set up, preferably for a few hours.