In a large bowl, whisk together flour, sugar, baking powder, baking soda, cinnamon, and salt.
In a medium saucepan over medium-low heat, melt butter. Stir in the buttermilk.
In a separate medium bowl, whisk together eggs and 1 cup hard cider.
Slowly pour half of the hot buttermilk into the egg and cider mixture, whisking while you pour. Then pour the entire egg/cider/buttermilk mixture into the saucepan with the rest of the buttermilk and whisk until well combined.
Pour hot mixture into the bowl with dry ingredients and stir until just combined, making sure no lumps remain.
Heat waffle iron and lightly brush with oil. Pour batter into iron, close iron, and bake until golden brown.
To make maple syrup: put maple syrup and ½ cup hard cider in a small saucepan and bring to a boil. Lower heat and let simmer for about 6 minutes, until mixture thickens a bit.
Serve waffles with hard cider maple syrup poured over the top.