In a large bowl, whisk together sourdough discard, mashed banana, oil, and eggs until cohesive and combined. This may take a little time to disperse the discard.
Add eggs, vanilla extract, and sugars. Whisk again until cohesive and combined.
In another large bowl, whisk together almond flour, all purpose flour, baking powder, baking soda, and salt. Add chocolate chips to top and toss with a little of the mixture. Make a well in the center of the dry ingredients.
Pour the wet ingredients into the dry and gently stir with a spatula to combine. Don't overmix, just until no dry flour streaks are visible. Let batter sit for 30 minutes (this rest gives you tall and beautiful muffins).
Preheat oven to 400 degrees F. Grease a muffin tin and fill with liners. Fill muffin liners to their tops with batter (not over the top, but you want them to be full). I like to fill every other muffin hole, as this gives you an even taller muffin. But if you want to, you can fill each muffin hole. Sprinkle a few extra chocolate chips on top of each muffin.
Place muffin pan in oven and turn heat down to 375 degrees F. Bake for 20 minutes, until a toothpick comes out with just a few moist crumbs. Remove muffins and let cool in the pan for 5 minutes, then transfer muffins to a wire rack.