Heat oven to 375°F. Spray 4 (4-inch) tart pans with cooking spray.
In medium bowl, beat butter and garlic salt with whisk. Separate dough into 8 biscuits; cut each into quarters. Dip biscuit pieces into butter mixture; divide pieces evenly among tart pans.
In large bowl, mix tomatoes, sugar, salt and Italian seasoning. Spoon equal amounts of tomato mixture on top of biscuit pieces in each pan. Top each with slice of cheese and 1/4 cup pepperoni.
Bake 14 to 16 minutes or until bread is dark golden brown and cheese is bubbly. Serve immediately.