To prepare this decadent dessert, spoon frozen yogurt into homemade tortilla bowls and drizzle with chocolate sauce.
Preheat oven to 375°. Wrap tortillas in slightly dampened paper towels. Microwave at HIGH 40 seconds. Combine sugar and ground cinnamon in a bowl. Coat tortillas with cooking spray; sprinkle 1 side of each tortilla with sugar mixture. Invert a 12-cup muffin pan; place tortillas, sugar side up, in the space between 4 muffin cups. Press gently to form a bowl. Bake at 375° for 20 minutes; cool in pan. Combine chocolate chips, milk, corn syrup, and instant espresso in a metal or glass mixing bowl. Place bowl over a saucepan of simmering water, whisking until smooth. Spoon 1/2 cup frozen yogurt into each tortilla. Top each with 1 tablespoon sauce; sprinkle sundaes evenly with flake salt.