1. Preheat the oven to 350 degrees F. Line a baking sheet with parchment paper or a silpat mat (or spray with nonstick spray).
2. In a medium bowl, whisk together the flour, sugar and salt. Mix in the yogurt and continue to stir and mix until the ingredients are well-combined and forming a dough. Turn out the dough onto a well-floured surface. Knead a bit until the dough comes together well, sprinkling in more flour if needed. Roll the dough into a rectangle (about 9x14-inches).
3. Spoon the pesto onto the rolled out dough, using the bottom of a spoon to spread it out evenly. Sprinkle with the chopped pepperoni. Top with 1/2 cup cheese.
4. Carefully roll up the dough into a log. It will be a little soft and precarious. Use a sharp knife to cut about 1/2-inch slices. Hold the sliced roll together with your fingers while you transfer it to the prepared baking sheet. Repeat with the remaining slices.
5. Bake 20 minutes, or until cooked through and lightly browned. Serve warm with sauce.