Preheat your oven to 400°F. While it heats, prepare the jalapenos by slicing them lengthwise and carefully removing the seeds and white membranes using a small spoon or knife. Arrange the hollowed jalapeno halves on a baking sheet, cut-side up, so they're ready to be filled. I like to line my baking sheet with parchment paper to prevent sticking and make cleanup easier.
Heat a large skillet over medium-high heat and add the ground turkey, breaking it apart with a spoon as it cooks. Continue stirring occasionally until the turkey is completely cooked through and lightly browned, about 8-10 minutes. Make sure to crumble it into small, bite-sized pieces rather than leaving large chunks. Once cooked, set it aside to cool slightly before mixing with the cheese base.
In a large mixing bowl, combine the cream cheese and mayonnaise, stirring until smooth and fully blended. Add 6 oz of the Mexican cheese and mix until evenly distributed. Then add all the spices: chile powder, red pepper flakes, cumin, cayenne pepper, salt, oregano, black pepper, and smoked paprika. Stir everything together until the spices are completely incorporated and the mixture is uniform in color. I prefer to mix the spices separately first to avoid clumping, then fold them into the cream cheese mixture for better distribution.
Add the cooked ground turkey from Step 2 to the creamy spiced mixture from Step 3, folding gently until everything is evenly combined. The filling should be thick, creamy, and studded with turkey pieces. Don't overmix—just fold until no streaks of cream cheese remain and the turkey is distributed throughout.
Using a small spoon or a piping bag, generously fill each jalapeno half with the turkey and cheese mixture from Step 4, mounding it slightly in the center. Once all peppers are filled, sprinkle the remaining 6 oz of Mexican cheese evenly over the top of each pepper, creating a layer that will melt and become golden during baking.
Place the filled jalapeno peppers in the preheated 400°F oven and bake for 25 minutes, or until the cheese topping is melted, bubbly, and lightly golden brown. The peppers should still have a slight firmness but not be completely soft. Remove from the oven and let cool for a few minutes before serving—the filling will set slightly as it cools, making them easier to handle.