Peel and devein shrimp. Rinse, and pat dry with paper towel. Place in a medium bowl.

In a small bowl, combine chili powder, cumin, oregano, garlic salt, onion powder, and pepper. Sprinkle over shrimp and toss until shrimp are well coated.

Heat a large skillet over medium-high heat. Add oil. Add shrimp to skillet and cook for 3 minutes, flip shrimp over and cook until pink all the way through, about 2 to 3 minutes. Remove from pan to a bowl to cool.

Cut baguette into 1/2″ thick slices, do not use heels of loaf. Spread a thin layer of butter on one side of each of the baugette slices. Toast bread in a large skillet over medium heat, in batches, until golden brown. Remove from skillet to a baking sheet, toasted side up.

Spread about 1 teaspoon (or more if you like) of guacamole over each crostini. Sprinkle with some queso fresco.

Once shrimp are cool enough to handle, butterfly each piece – cutting through the back (where the vein was) and laying the shrimp open on top of the cheese. Serve immediately.