Preheat oven to 190 C / Gas 5. Lightly grease a 23x33cm or similar sized baking dish.
Bring a large pot of lightly salted water to the boil. Add the penne and cook until al dente, about 8 to 10 minutes. Drain and set aside.
Meanwhile, place the olive oil into a frying pan set over medium-high heat. Stir in the onion and cook until soft and translucent, about 5 minutes. Add the venison and cook until crumbled and no longer pink, about 10 minutes. Drain, if necessary. Stir in the pasta sauce, basil and garlic granules. Season to taste with salt and pepper and turn off the heat.
Assemble the pasta bake by spooning a layer of the venison sauce over the bottom of the prepared baking dish. Sprinkle the sauce with Parmesan cheese and layer with cooked penne. Top with the sauce, layer with penne and half of the mozzarella. Repeat the layers to use the remaining ingredients, ending with a layer of mozzarella cheese. Cover the dish with foil.
Bake in preheated oven for 20 minutes. Remove the foil and bake until the cheese topping is light gold, about 10 minutes more.