Cook the shrimp in a skillet set over high heat until just cooked through, about 3 minutes.
Spread each tortilla with 2 tablespoons of hummus, leaving a 1/2-inch border around the edge. Drizzle with toasted sesame oil.
Scatter the avocado over the hummus. Use a fork to gently mash the avocado.
Arrange the cooked shrimp, red onion, and scallions over half of each tortilla. Sprinkle with red pepper flakes. Fold the tortillas in half.
Heat the olive oil in a skillet over medium-high heat. Add the quesadillas and cook 3-4 minutes on each side, or until golden brown and lightly crisp. Cut each quesadilla into 4 wedges and server immediately.