Mix the pork, sausage, egg, scallions, 1 teaspoon salt, 1/2 teaspoon pepper and about three-quarters of the crushed gingersnaps in a large bowl with a spoon or your hands until combined; refrigerate 1 hour. Dampen your hands and form the mixture into about 20 meatballs, 3/4 inch each.
Preheat the oven to 375 degrees F. Add the olive oil to a large cast-iron skillet or Dutch oven and swirl to coat. Add the meatballs in a single layer and top with the onion, garlic and poblano. Sprinkle with the chili powder. Bake until the meatballs are firm and the vegetables start softening, about 8 minutes.
Add the tomatoes to the skillet along with the Worcestershire sauce, brown sugar, the remaining gingersnaps, the chicken broth, hot sauce and 1 cup water. Stir gently, carefully loosening the meatballs from the pan and mixing them into the sauce. Return to the oven and bake until the meatballs are tender and the sauce thickens, about 40 more minutes.