Step 1

Preheat oven to 350 degrees F (175 degrees C). Spread pork ribs on a baking sheet; season with salt and pepper.

Step 2

Bake in the preheated oven until lightly browned, about 30 minutes.

Step 3

Whisk hoisin sauce, sugar, soy sauce, white wine, tomato paste, garlic, chili-garlic sauce, and five-spice powder together in a bowl.

Step 4

Grease a slow cooker insert with cooking spray. Transfer pork ribs to the pot. Cover evenly with hoisin sauce mixture.

Step 5

Cook on Low, stirring halfway through, until pork ribs are tender, about 8 hours.