In a blender or food processor, combine the avocado, sour cream (or Greek yogurt), cilantro, garlic clove, lime juice, and a pinch of salt. Blend until completely smooth. If it's too thick, add a tablespoon of water at a time until it reaches a drizzling consistency. Transfer to a bowl and set aside.

Pat the peeled and deveined shrimp dry with paper towels. In a medium bowl, toss the shrimp with the chipotle chili powder, smoked paprika, cumin, garlic powder, and salt until evenly coated.

Heat the olive oil in a large skillet over medium-high heat. Once the oil is shimmering, add the shrimp in a single layer, being careful not to overcrowd the pan (work in batches if necessary).

Cook for 1-2 minutes per side, until the shrimp are pink, opaque, and cooked through. Remove from heat immediately to avoid overcooking.

Warm the tortillas according to package directions. You can do this in a dry skillet, over a gas flame, or wrapped in a damp paper towel in the microwave.

To assemble, lay a warm tortilla flat. Add a small handful of shredded cabbage, top with 3-4 pieces of chipotle shrimp, and drizzle generously with the avocado crema. Garnish with crumbled cotija cheese and sliced jalapeños, if desired. Serve immediately with extra lime wedges on the side.