Place dry ingredients in a mixing bowl; combine. Mix eggs, butter, and buttermilk in a separate bowl. Slowly add dry ingredients; once combined, set aside to rest for 10 minutes. Toss squash slices in oil; season with cinnamon and nutmeg; bake at 450 degrees until golden. Cook waffles in waffle iron; garnish with squash and candied pecans. Top with fried sage leaves. Serve.