In a large mixing bowl, add water and sprinkle yeast over it. Allow to sit for 5 minutes. At the end of 5 minutes, the mixture should be bubbly.

Add the buttermilk, melted butter, eggs, vegetable oil, salt, sugar and both flours. Beat ingredients together until smooth.

Cover the bowl with plastic wrap and refrigerate overnight.

In the morning, preheat the oven to 450 degrees.

Spoon the batter into the wells of a non-stick donut pan. Fill each donut well about 1/2 full.

Bake for 10 minutes. Remove from oven and remove from pan to a cooling rack.

Whisk together the maple syrup, vanilla extract and confectioners sugar until smooth.

Glaze the donuts with the maple syrup glaze and serve.