Preheat the oven to 350℉.
Place chopped shrimp and scallops in a bowl and dry them with a paper towel.
Add chili powder, garlic powder, onion, powder, cumin, cayenne pepper, sea salt, and black pepper to the bowl and stir to coat the shrimp and scallops.
Heat a lightly oiled small cast iron skillet over medium heat.
Cook the shrimp and scallops for about 5-6 minutes or until the shrimp turns pink.
Remove from heat and set aside.
In a 2 quart saucepan over medium heat, melt the butter. Add the jalapeños and stir.
Add the flour to the saucepan and cook for 3-4 minutes.
Slowly whisk in the milk, whisking continuously to thicken (about 5 minutes). While thickening the sauce, add the sea salt.
Remove the sauce from the heat and add one cup of oaxaca cheese to the sauce, whisking until smooth. Set aside.
Fill each tortilla with seafood mix, a little cheese, and roll tightly. Place the rolled tortillas seam side down into a 11x7 baking dish.
Once all of the tortillas are rolled, pour the sauce over the tortillas. Sprinkle any remaining cheese on top.
Bake in a preheated oven for 20 minutes, or until hot and bubbly.
Remove the baking dish from the oven and allow to cool for 10 minutes before serving.