Preheat the oven to 325 degrees F.
Add the flour, chia seeds, cinnamon, and baking powder to a bowl and mix.
In a separate bowl, whisk together the maple syrup, milk, and vanilla.
Combine the wet and the dry ingredients and whisk.
Grease the donut pan with a small amount of coconut oil. Pour the donut batter into the donut molds and bake for 18 minutes, or until a toothpick inserted comes out clean. Allow the donuts to cool in the pan for at least 10 minutes before gently removing them
Prepare the cinnamon sugar coating. Mix the cinnamon and sugar together in a shallow dish large enough to dip a donut in. If you would like to cut down on oil, brush the donuts with water and dip them into the cinnamon sugar to completely coat the tops. If you don't mind oil, brush the donuts gently with melted coconut oil and dip the donuts to coat them in the cinnamon sugar. The oil-free version is almost the same, but in testing both, the cinnamon sugar does adhere better to the donuts that are brushed with oil. Serve and enjoy!