Grease a 12-count or 24-count mini muffin pan with oil or cooking spray. Use a brush to distribute the oil evenly inside each well.
Place a piece of wonton wrapper on a chopping board. Spray it with cooking spray and then use a pastry brush to evenly distribute the oil over the entire surface. Alternatively, pour a small amount of oil into a bowl. Then, dip a brush into the oil and brush the entire surface of the wonton with a thin layer of oil.
Flip the wonton wrapper over and do the same to the other side. Stack another wonton wrapper directly over the first wrapper. Then, brush or spray oil over the top side wonton wrapper. Continue doing this until you have a stack of 6 or 12 wonton wrappers. Slice the stack of wonton wrappers diagonally, so that you have 2 stacks of triangular wrappers of equal size.
Take one triangular wrapper and lay it over both your hands. The right angle of the triangle should be facing down and the longest edge of the triangle should be facing up. Use your hands to fold the two top corners together, creating an oblong cone or boat-like shape with the wrapper. The two corners should stick together because of the oil on the wrapper. Look at the photos or video below for reference.
Transfer the folded wrapper to a well in the mini muffin pan. Flatten the bottom and try to press the wrapper against the sides of the well. Continue folding and transferring the rest of the wrappers to the muffin pan.
Bake the wonton wrappers. If your muffin pan is made of a dark-colored metal, bake the wrappers for 7 to 8 minutes, rotating the pan around at the 4-minute mark to ensure even baking. Check the wonton cups at the 7-minute mark to see if they’re golden brown. If they are, remove the muffin pan from the oven. If not, bake the wonton cups for another minute or two. If your muffin pan is made of a light-colored metal, bake the wrappers for an additional minute or two.
Remove the wonton cups from the oven and let them cool for a few minutes before transferring to a cooling rack. If you are baking a second batch, let the muffin pan cool completely before greasing the wells again for the second batch. Alternatively, you can use a clean muffin pan.
Do not be alarmed by the powdery residue on the wonton wrappers. It’s just starch that manufacturers apply between wrappers to prevent them from sticking together. The wrappers are fine to eat.