In a large mixing bowl, whisk together flour, salt, and baking powder until well blended. Gradually incorporate vegetable oil and warm water, mixing until a soft dough forms. Knead the dough on a floured surface for about 5 minutes, until it feels smooth and elastic. Cover the dough with a clean cloth and let it rest for 30 minutes to relax.

While the dough rests, heat a skillet over medium heat and brown the ground beef or turkey, breaking it apart with a spatula until cooked through. Drain any excess fat, then stir in the taco seasoning mix and a splash of water. Cook for about 5 minutes, until the mixture thickens and becomes fragrant. Remove from heat and allow the filling to cool slightly.

After the dough has rested, divide it into 8 equal portions and roll each into a ball. On a lightly floured surface, flatten each ball with a rolling pin into a 6-inch circle, ensuring an even thickness. Keep the circles separate to prevent sticking.

Take one dough circle and place about 2 tablespoons of the cooled meat filling on one half. Sprinkle a little cheddar cheese, onions, diced tomatoes, cilantro, and, if desired, jalapeños over the filling. Carefully fold the other half of the dough over the filling and seal the edges using a fork.

In a deep frying pan, heat vegetable oil to 350°F (175°C). Gently place a few taco pockets in the hot oil, taking care not to overcrowd the pan. Fry for about 3-4 minutes on each side or until they turn golden brown and crispy.

Arrange your spicy crispy Mexican taco pockets on a serving platter. Pair them with a side of sour cream and salsa for dipping.