Preheat the oven to 450°F. Arrange a rack in the center of the oven. Measure a piece of parchment paper big enough to line the bottom of a big, heavy baking sheet and set it aside. Place the unlined baking sheet in the oven to heat up as the oven preheats.

Spread refried beans on one side of each tortilla, about 1 heaping tablespoon per tortilla, and arrange in a single layer on a platter or another baking sheet. Dust each one with chili powder, if using. Put the cheese in a convenient location so that you’re ready to go.

Once the pan has preheated for 10 minutes or so, remove it from the oven. Carefully line with the piece of parchment and spray generously with cooking spray. Arrange the tortillas on the baking sheet in a single layer, bean side up. Top each tortilla with cheese, about ¼ cup per taco mounded in the center.

Place the baking sheet in the oven and bake until the cheese has melted and the tortilla is soft, just 1 to 2 minutes. Remove from the oven and immediately fold each tortilla over using a spatula to make little tacos. Use the back of the spatula to lightly press each one down to adhere.

Place back in the oven and bake until lightly crisp on the bottom, 5 to 7 minutes. Flip and cook until gooey with crispy cheese bits, 5 to 7 more minutes.

Let cool for a few minutes. Serve with salsa, sour cream, and/or guacamole for dipping or topping.