In a small bowl, mix together the soy sauce, balsamic vinegar, crushed red pepper, chilli powder and sugar. Set aside.
Heat the olive oil in a wok or pan over medium-high heat. Add the garlic and saute until fragrant, about 30 seconds. Add the shrimps and cook until both sides are pink, about 2 minutes on each side.
Add the sauce mixture and stir until the shrimps are coated, about 2-3 minutes.
Remove from the heat and garnish with green onion and basil. Serve the spicy shrimp with rice, noodles or vegetables.