Preheat the over the 375ºF. Oil a large baking pan (9×13 inch) or small cookie sheet with sides. In a small bowl, blend the oil into the nut butter. (If the nut butter is very thick, use the larger amount of oil. If it is thin, use the lesser amount.) Mix in the apple butter, maple syrup, stevia, maple flavouring, and vanilla. Place sesame seeds in a large mixing bowl. Stir in the nut butter mixture. Add the flour and salt, and mix well. Press the mixture evenly and firmly into the bottom of the pan or cookie sheet to about ¼ inch thick. Bake for 15-18 minutes. Cool completely before cutting.