Make sure shrimp are completely de-thawed. Pat them dry with a paper towel.
Add shrimp to gallon size Ziploc bag, along with sriracha, peach jam, and garlic powder. Massage the marinade into the shrimp, store in refrigerator for at least one hour.
Thread onto skewers (I use two skewers to keep the shrimp in place). If using wooden skewers, make sure they are well soaked in water beforehand so they don't burn.
Grill over high, direct heat for 2.5 minutes on each side, basting each side with basting liquid. Serve while hot.
Notes
If you do not have access to peach jam, another light flavored jam will work fine. Apricot or mango preserves are excellent. Cherry is also good!