Bring the butter and water to a boil in a small saucepan. Add the flour and salt and stir the mixture until a ball of dough forms and pulls away from the side of the pan. Remove the pan from the heat and add the vanilla extract and eggs, one at a time, using an electric mixture to beat everything together. (Make sure you are using a stainless steel saucepan. If you are using a non-stick saucepan, transfer the mixture to a bowl before using an electric mixer.)

Place the dough in a pastry bag with a small star tip. Turn a 12-cup muffin tin over so the bottom of the pan is face up and cover the inverted cups with plastic wrap. Spray the entire surface with oil. Starting at the bottom of the cup, pipe the dough up and around the inverted muffin cups in a spiral to form a bowl, making sure there are no gaps in the dough. Place the muffin pan in the freezer for at least 1 hour.

Pre-heat the air fryer to 370ºF.

Remove the dough cups from the muffin pan using the plastic wrap and a butter knife to pop the dough bowls off the pan gently. Shape a piece of aluminum foil into a ball to fit inside the dough bowl. (This will hold the shape of the bowl while it is air-frying.)

Air-fry the churro bowls in batches. Place two or three bowls face down into the air fryer basket. (Hold remaining dough bowls in freezer until ready to air-fry.) Spray the bowls with vegetable or canola oil and air-fry at 370ºF for 7 minutes. Turn the bowls over, remove the ball of aluminum foil and spray the inside of the bowls with a little oil. Air-fry for an additional 4 to 5 minutes until the bowls are light brown in color.

While the churro bowls are air-frying, combine the sugar and cinnamon in a large bowl. Remove the churro bowls from the air fryer and immediately place them in the cinnamon sugar. Sprinkle and coat all sides of the bowls with the cinnamon sugar.

Serve the churro bowls warm or at room temperature. Fill the bowls with ice cream, fruit, whipped cream, pudding, mousse or any delectable treat. (If you are making these bowls ahead of time, stop after step 5. When you are ready to serve, re-heat the churro bowls in the air fryer at 330ºF for 2 minutes and proceed with the recipe.)