Heat oven to 400°F. In 12-inch nonstick skillet, cook bacon over medium heat, turning once, until crisp. Drain on paper towels; crumble bacon. Drain drippings from skillet.
In skillet, cook beef and onions over medium-high heat, stirring occasionally, until thoroughly cooked; drain. Stir in bacon, baked beans, kidney beans with reserved 1/4 cup liquid, brown sugar, ketchup and vinegar. Reduce heat to medium-low; cook until bubbly, stirring occasionally. Pour into ungreased 11x7-inch (2-quart) glass baking dish.
Unroll dough; separate into 12 strips. Arrange strips in lattice design over bean mixture, overlapping as necessary to fit. Brush dough with milk; sprinkle with sesame seed.
Bake 15 to 20 minutes or until breadsticks are golden brown and filling is bubbly.