In a large mixing bowl, whisk together all marinade ingredients until well combined.
1 Tbsp garlic, ½ Tbsp salt, 1 Tbsp brown sugar, 1 Tbsp honey, 2 Tbsp oyster sauce, ½ Tbsp soy sauce, ½ Tbsp dark soy sauce, 2 tsp five spice powder, 1 tsp cinnamon, 2 Tbsp char siu sauce
Add the pork and coat thoroughly in the marinade. Cover and refrigerate overnight (at least 8 hours, up to 24 hours for deeper flavor).
1 lb pork shoulder
Preheat the oven to 425°F. Line a baking sheet with parchment paper.
Arrange the pork on the baking sheet, reserving the leftover marinade for basting.
2 Tbsp honey diluted with 2 tsp water along with leftover marinade
Bake for 15 minutes. Remove from the oven, baste both sides with the reserved marinade, and return to the oven.
Bake for another 15 minutes. Baste again on both sides.
Increase the oven temperature to 450°F and bake for an additional 15 minutes, or until the pork is caramelized and slightly charred at the edges. Flip again if necessary.
Remove from the oven and let rest for 10 minutes before slicing.