Spicy Roasted Shrimp Sandwich with Chipotle Avocado Mayonnaise

• 1 pound medium shrimp peeled and deveined
• 1 tablespoon olive oil
• 1 teaspoon cumin
• 1 teaspoon garlic powder
• ½ teaspoon chili powder
• Kosher salt and freshly ground black pepper to taste
• chipotle avocado mayonnaise
• 1 baguette cut it into 3-4 equal pieces, toasted, for serving
• Romaine lettuce leaves for serving
• Sliced avocado for serving

For the Chipotle Avocado Mayonnaise

• 1-3 chipotle peppers in adobo sauce
• 1 avocado pitted and chopped
• ¼ cup mayonnaise
• ¼ cup Greek yogurt
• Juice of 1 lime
• ¼ teaspoon salt