Preheat oven to 350 degrees.
Brown the breakfast sausage in a large skillet over medium/high heat until no longer pink. Drain (if needed) and crumble. Set aside to cool.
In a large bowl beat the butter and sugars until fluffy.
Beat the eggs into the butter mixture, one at a time.
In a medium bowl whisk together the flour, baking powder, baking soda, cinnamon, and salt.
Alternately add the flour mixture and Greek yogurt into the butter mixture, beating after each addition.
Using a wooden spoon or spatula, gently fold in the blueberries and the cooled breakfast sausage.
Spoon the batter evenly into a 9x13 casserole dish that has been prepared with baking spray.
Sprinkle the top of the batter evenly with nuts before baking. (optional)
Bake for approximately 50-55 minutes or until a toothpick inserted in the center comes out clean.
Cool for 10 minutes and cut into squares.
Serve with plenty of maple syrup and enjoy!