Unroll crescent rolls on a lightly floured surface; cut into triangles. Top the widest end of each triangle with 4 pieces pepperoni, then a piece of string cheese. Roll up and tuck corners in to keep cheese from oozing out. Place on a baking sheet.
Lightly sprinkle tops with garlic powder. Bake for 12 to 15 minutes, or until golden brown. Sprinkle with Italian seasoning. Serve warm with marinara sauce for dipping.