Make batter: In a large bowl, whisk together flour, 2 tablespoons sugar, baking powder, baking soda, and a large pinch of salt. In another large bowl, whisk together buttermilk, 6 tablespoons butter, eggs, and vanilla. Slowly add dry ingredients into wet ingredients, mixing with a wooden spoon until just combined.
Make cinnamon sugar: In a shallow bowl or plate, mix together remaining ½ cup sugar and 1 tablespoon cinnamon.
Make cinnamon ganache: Place chocolate chips and remaining 1 teaspoon cinnamon in a medium, heat-proof bowl. In a small saucepan over medium-low heat, heat heavy cream just until it bubbles, about 5 minutes. Pour hot cream over chocolate chips. Let sit 5 minutes, then whisk until smooth.
Cook waffles: Heat waffle iron according to manufacturer’s instructions. When the iron is hot, grease with cooking spray and cook waffles until deeply golden.
Brush waffles with remaining 6 tablespoons melted butter, and immediately dip into cinnamon-sugar mixture to coat.
Slice into strips and serve with ganache for dipping.
