Prepare the pizza crust. Place flour, salt, sugar, and dry yeast in large mixer bowl.
Mix with a dough hook for 30 seconds on low speed.
Whisk together the warm water and oil. Add liquids to the flour mixture and mix on low speed for 5 minutes.
Remove the dough from the mixer and gently shape into a large ball. Let sit at room temperature for at least 20 minutes before stretching.
Lightly coat a large sheet pan (13”x18”x1”) with cooking spray. Sprinkle pan with cornmeal and set aside. Place dough ball in center of pan and flatten dough by rolling or spreading with fingers to the rim of pans. Keep edges thicker than center to create a crust when baked.
Prepare the pizza toppings. Heat tomato puree and refried beans in saucepan over medium heat. Mix well to combine and season with 2 tablespoons taco seasoning.
In a separate pan, place the corn, green peppers, diced tomatoes and remaining 2 teaspoons taco seasoning in a large skillet.
Cook for 10 minutes, stirring occasionally. Drain off any excess liquid.
Assemble the pizza. Spread tomato/bean mixture onto pizza crust followed by tomato corn-pepper mixture. Sprinkle on cheddar cheese and bake until crust is lightly browned: Conventional oven: 475°F for 15-18 minutes. Convection oven: 450°F for 15 minutes.
Remove and let sit for at least 5 minutes before slicing. Cut into 10 squares and top with shredded lettuce and salsa. Serve immediately.*May use prepared pizza crust