Preheat oven to 450°F. Coat a rimmed baking sheet with oil.
Using your hands, crumble the pork sausage and mix pork, turkey, eggs, garlic, breadcrumbs, milk, fennel, chopped sage, 2 teaspoons of the salt, and 1/2 teaspoon of the pepper in a large bowl until incorporated.
Roll into 1" balls, making sure to pack firmly.
Transfer balls to prepared baking sheet, packing them snuggly. Roast meatballs until firm and cooked through, about 15 minutes.
Meanwhile, heat Just Jan's Cranberry Raspberry Relish.
Using a pastry brush, generously coat meatballs with 1/3 cup cranberry sauce.
Return meatballs to oven and continue to bake until glaze is shiny and caramelized, about 5 minutes more.
Shake sheet to coat meatballs with sauce.
Transfer remaining sauce to a serving bowl and transfer meatballs to a serving platter. Top meatballs with sage leaves before serving, if using.