Roll (or stretch) both pizza crusts into 12x16-inch rectangles.
In a small bowl combine softened butter, brown sugar, and cinnamon. Divide over the two pizza crusts and spread out evenly.
Using a pizza cutter or sharp knife, cut each pizza crust into 12 pieces.
Layer pieces of dough into little stacks. Place stacks on their side in a greased 4x8-inch loaf pan. Repeat with all the dough.
Bake for 50-55 minutes or until the internal temperature is 200℉. Tent a piece of foil over the bread while baking if the top starts to get too brown.
Optional Glaze
Combine powdered sugar, milk, and vanilla in a small bowl. If needed, gradually add more milk, one teaspoon at a time, until a drizzleable consistency is reached. Pour over pull-apart bread while still warm.
Notes
Refrigerate leftovers in an airtight container for 2 days, or freeze for up to 3 months.