Add the olive oil to a large sauté pan and heat over medium. Add the onions, garlic, and tomatoes. Bring to a simmer and stir frequently. The goal is to reduce the liquid, so continue cooking over medium heat.
Add the carrots and the salt, pepper, and spice blend. Cook for about 20 minutes, continuing to stir the mixture to prevent burning.
Add the ground meat and break apart with a spatula and continue to cook until the meat is cooked through. Turn down the heat.
Chiffonade 10-12 leaves of basil, set aside. Add the basil to the meat and veggie mixture before spooning into squash.
While the meat is cooking, slice the stems off of the squash. Use a spoon to score a circle about 1 cm from the edge. I suggest using a cookie dough scooper (basically a small ice cream scoop) to scoop out the innards of each squash, being careful to keep the outter flesh intact.
Set the squash in a 9 x 13 in baking dish.
Spoon the meat and veggie mixture into the squash and overfill.
Bake for 30 minutes or until a knife easily pierces the squash. Top with a sprig of basil and serve.