In the bowl of a stand mixer with a paddle attachment, cream together the granulated sugar, butter, and orange zest.
Prepare the vegan egg replacer according to package directions. Add the "egg" mixture to the butter mixture in the bowl.
Add the vanilla extract and continue mixing until fully incorporated.
In a medium-size mixing bowl, combine the all-purpose flour, baking powder, and salt. Add half of the dry ingredients to the butter-sugar mixture. Mix on medium-low speed to incorporate then mix in 1 tablespoon plant milk. Add the remaining dry ingredients and an additional 1 tablespoon plant milk. Mix until the dough comes together; it will be very crumbly.
Butter, or spray with non-stick baking spray, a 9x13-inch glass baking pan. Use your hands to press 2/3 of the dough into the dish, forming a 1-inch layer to cover the bottom completely.
Pour the cherry pie filling in an even layer over the dough to cover completely.
Sprinkle the remaining dough over the top. Use as little or as much topping as you like; you may have a little extra depending on your preference.
Bake for 40 minutes, until the edges and top are golden and the center is set. Set aside for at least 30 minutes to set and cool.