Cover cookie sheet with foil for easier cleanup. Preheat oven to 400 degree F. Cut around the edge of each pita bread round, splitting each into 2 circles and making a total of 8 circles. Save 4 circles.
Toast 4 pita circles in a toaster one at a time. (If pita circles are too large for the toaster, place them on a cookie sheet and bake for 2 minutes.)
Spread each toasted pita circle with some of the pizza sauce. If using large Canadian-style bacon slices, cut each slice into 4 pieces. Divide pepperoni or Canadian-style bacon and green pepper evenly among toasted pita circles. Top each with some of the cheese.
Place untoasted pita circles on top. Place on cookie sheet. Bake 8 to 10 minutes or until hot and cheese has melted. Cool on wire rack for 2 to 3 minutes. Cut each pizza into 4 pieces, if desired.