In a small bowl, combine the flour, cornmeal, baking powder, baking soda, and 1/2 teaspoon salt.
In a large measuring cup combine the buttermilk, egg, and 3 tablespoons maple syrup and stir with a fork. Stir into the flour mixture with a spatula until just combined. Mix in the diced apple and sausage crumbles.
Heat a pancake griddle over medium-low heat and then grease with a small amount of butter. Drop ladles of batter to form 4-inch pancakes, cooking pancakes for 2 to 3 minutes before flipping, or until the batter puffs up and bubbles form. Flip pancakes and continue to cook for an additional 1 to 2 minutes, until cooked through and nicely browned. Top with Cinnamon Walnut Butter and additional maple syrup, if desired.
Combine the butter, maple syrup, cinnamon, vanilla, and salt in a bowl and mix until well blended. Serve with pancakes.