In a large bowl, combine flour, baking powder, and salt. Whisk to combine. Add water and oil to the dry ingredients. Mix together until it starts to form a rough ball of dough.
Turn the dough onto a lightly floured work surface and knead the dough for about 2 to 3 minutes, or until it's smooth and soft. Cover the dough, and set aside to rest for about 15 minutes to make it easier to roll out.Preheat your oven to 400°F. Line 2 large baking sheets with parchment paper and set aside.
Uncover the dough, and divide in half. Roll each half of dough into about ⅛th of an inch thick. Working with one half of the dough, dollop small amounts of pizza sauce (about ¼ teaspoon) over the top of the dough - leaving 1 inch of space between each dollop. Top each dollop of sauce with mozzarella (and any other toppings you like).
Brush a light layer of water along the edges around the dollops of sauce and cheese (this is to help adhere the top dough). Take the other rolled half of dough and place it overtop the sauced and cheesed dough. Press down the edges around the filling to seal.
Using a knife or pizza/pastry cutter, trim off the excess dough on the sides, and then cut out mini bites. Using a knife or skewer, pierce a small hole on top of each mini bite to allow steam to escape while it bakes.
Transfer the portioned pizza bites to your parchment lined baking sheets, leaving about 1 inch of space between each one. Bake in the center of your preheated 400°F oven for 10 to 15 minutes, or until golden brown on top. Cool slightly before serving!