Preheat oven to 350°F. Spray a 12-cup bundt or fluted tube cake pan with cooking spray.
Remove dough from both cans but do not unroll. Place both pieces of dough in pan in a circle; pinch ends together to seal into 1 ring.
Bake 35-40 minutes or until golden brown. Cool in pan about 10 minutes. Remove bread to a cooling rack and cool completely 30-40 minutes.
Carefully slice bread in half horizontally. Pinch or tear out bread from top and bottom halves, leaving about a ¾-inch shell.
In a small bowl, stir mayonnaise and garlic together. Spread mayonnaise mixture on cut sides of both pieces of bread rings. Place bacon on top ring and press gently into mayonnaise. Add avocado on bottom bread ring.
Top with turkey, tomatoes, spinach and red onion. Carefully replace top bread ring and press lightly. Cut into 8 wedges to serve.