Step 1

Mix the brown sugar, fajita seasoning, and paprika in a bowl. Rub both sides of the pork spareribs with the brown sugar mixture. Place the spareribs in a 9x13-inch baking pan; cover and refrigerate overnight.

Step 2

Preheat an oven to 250 degrees F (120 degrees C). Whisk together the beer, garlic, honey, Worcestershire sauce, and mustard in a bowl. Set aside.

Step 3

Tear off 2 large sheets of heavy duty aluminum foil and lay them shiny-side down. Place a rack of spareribs on each sheet, meaty-side up. Tear off 2 more sheets of foil and place them on top of the ribs, shiny-side up. Begin tightly folding the edges of the foil together to create a sealed packet. Just before sealing completely, divide the beer mixture evenly into each packet. Complete the seal. Place the packets side-by-side on an 11x14-inch baking sheet.

Step 4

Bake in the preheated oven until the ribs are very tender, 3 hours and 30 minutes to 4 hours. Carefully open each packet, and drain the drippings into a saucepan. You may only need the drippings from one packet. Set ribs aside. Simmer the drippings over medium-high heat until the sauce begins to thicken, about 5 minutes. Brush the thickened sauce over the ribs.

Step 5

Preheat the oven's broiler and set the oven rack about 6 inches from the heat source.

Step 6

Place the ribs back into the oven and broil until the sauce is lightly caramelized, 5 to 7 minutes.