**Prepare the meat mixture** In a large mixing bowl, combine ground beef, pork (if using), breadcrumbs, egg, garlic powder, onion powder, salt, and pepper. Use your hands or a wooden spoon to mix until just combined, being careful not to overmix.

**Make the filling** In a separate bowl, stir together the softened cream cheese, shredded cheddar (or pepper jack), and diced jalapenos. If the mixture is too thick, add a splash of milk to help blend.

**Shape and fill** On a sheet of parchment paper or lightly greased foil, pat half of the meat mixture into a loaf shape, about 1 inch thick. Spread the jalapeno-cheese filling on top, leaving a small border around the edges. Carefully place the remaining meat mixture on top and shape into a loaf, sealing the edges to enclose the filling completely.

**Glaze (optional)** Transfer the loaf to a baking sheet or loaf pan. If desired, spread ketchup or barbecue sauce on top for extra flavor and color.

**Bake** Preheat your oven to 350°F (175°C). Bake the meatloaf for 50–60 minutes, or until the internal temperature reaches 160°F (71°C). If the top browns too quickly, loosely cover with foil during the last 10–15 minutes of baking.

**Rest and serve** Let the meatloaf rest for 5–10 minutes before slicing. This helps keep the filling and juices intact. Slice and serve warm.