Stir the melted butter, powdered sugar, graham cracker/vanilla crumbs, and almond butter together, until all of the ingredients are incorporated.
Line a 9 x 13 inch dish with foil. Drape the foil over the sides of the dish so that you can easily remove it once the bars set. Press the mixture into the bottom of the dish.
Melt the vegan chocolate in a double boiler and spread the chocolate over the almond butter mixture.
While the chocolate is still warm, cut the bars. Allow to set for at least an hour.