Preheat the oven to 350°F (175°C). Line a rimmed baking sheet with foil and set aside.

Melt the butter in a medium skillet over medium heat. Add the onion and garlic and cook, stirring often, for 4 to 5 minutes, until the onion is soft and translucent.

Take the skillet off the heat and let the onion mixture cool for about 5 minutes, so it doesn't start cooking the eggs when you mix everything together.

In a large bowl, add the ground turkey, the cooled onion mixture, almond flour, Parmesan, eggs, parsley, Italian seasoning, 1 tablespoon of the sugar free ketchup, salt and pepper.

Mix with clean hands or a fork until everything is evenly combined. Stop as soon as it comes together; overmixing makes the meatloaf dense.

Shape the mixture into a loaf about 9 inches long and 5 inches wide on the prepared baking sheet.

Spread the remaining ½ cup of sugar free ketchup over the top and sides of the loaf.

Bake for 45 to 50 minutes, until an instant-read thermometer in the thickest part of the loaf reads 165°F (74°C).

Let the meatloaf rest for 10 minutes, then cut it into 8 slices and serve.