Preheat oven to 350 degrees.
In a large mixing bowl, beat together the vegan butter, peanut butter and brown sugar until light and fluffy.
Make a flax egg by mixing together the flax meal and water in a small bowl. Set aside for a moment to thicken, then add the flax egg to the peanut butter/butter/sugar mixture. Then add the vanilla and beat again, until fully combined.
In a food processor, pulse the oats for a minute or so until it is pretty fine flour, but still has some texture. Stir the baking soda, baking powder, cornstarch and salt into the oat flour. Slowly add the oat flour mixture to the wet ingredients, beating each time until everything is combined.
Stir in the vegan candies and dark chocolate chips.
Scoop dough into a prepared 9x13 in. baking pan, and press down in an even layer. Bake at 350 degrees for 15-20 minutes or until fully cooked and tooth pick comes out clean. Let cool completely. Slice into squares and devour!