In the bowl of a stand mixer, combine butter (df sub), shortening, and sugars. Beat well, adding eggs or egg substitute, and vanilla, one at a time, mixing thoroughly, until mixture is light and fluffy. In a separate bowl, blend together flour, baking soda, baking powder, and salt. Add to the wet mixture in the mixer and stir until combined. Stir in chocolate chunks. Cover and chill dough for at least 4 hours or overnight. When ready to bake, preheat oven to 375 degrees F. Line two cookie sheets with parchment paper and set aside. Scoop cookie dough into balls just larger than a golf ball – about 1 oz in weight. Arrange six dough balls on each cookie sheet, being careful not to overcrowd. Chill remaining dough in the fridge while cookies bake so remaining dough doesn’t soften much. Bake scooped cookies on tray for 8-9 minutes. About halfway through the baking cycle (4 minutes) rotate or turn the cookie sheets to ensure even baking. Check cookies at 8 minutes, they should be slightly puffed and just starting to brown on top. Once done, remove from oven, and place the sheet on a wire rack. Cool the cookies 2-3 minutes on cookie sheet before removing from the sheet. Allow to cool on the parchment paper, on a wire rack until completely cool.