I've been searching for a chalupa recipe, too. This isn't perfect, but my family liked it. If anyone improves it, please let me know! Thanks!

Mix well or sift together 4 cups flour, 1 tsp salt, and 4 tsp baking powder. Cut in 1/4 cup shortning (can be hard because there is lots of flour and it will not look crumbly). Ad 1-1/4 to 1-1/2 cups water, slowly, stirring to form a stiff dough. Knead until smooth. Roll out THINLY (about 1/8 inch thick); when it cooks, it will puff up. Can roll in two ways...1) take a ball of dough (about 1/4 cup) and roll into an oval shape OR 2) roll out all the dough between 2 sheets of waxed paper and cut out circle shapes with a coffee can or a bowl. Heat about 2 inches of oil in a heavy pan over medium-high heat (325 to 350 degrees). Fry shapes as long as you like...the more the crisper but also the less flexible and the more puffy. (I did about 45 seconds to 1 minute per side...experiment with the first one, because it depends on how hot your oil is.) Be sure to flip over to brown the other side. Drain on paper towels and add meat and other toppings.

** Would be really tasty with cinnamon and sugar, peanut butter and jelly, butter or honey.