1.5litresgrapeseed oil or neutral flavoured frying oil
In a large bowl add the warm water, yeast and 1 tablespoon of sugar. Whisk to blend and let sit for 7-10 minutes until a "raft' forms on the top of foamy-looking yeast.
Add the remaining sugar, melted butter, egg, egg yolk and buttermilk to the yeast mixture and whisk to combine.
Add the flour and salt and using a hand mixer or stand mixer with a hook attchment blend until the flour is combined with the liquid and the dough begins to become smooth looking and pulls away from the edge of the bowl. If using a hand mixer I find I need to remove the dough from the bowl once it is blended and then knead by hand for about 5 minutes until the ball of dough becomes smooth and less sticky.
Spray the bowl with cooking spray and let the dough rise in the bowl covered with plastic wrap or a clean towel for about 90 minutes. The dough should double in size.
Lightly flour a flat surface and use a rolling pin to roll the dough out to a rectangle that is a 1/2" thick.
Using a measuring tape and a sharp knife or pizza cutter, cut the dough into 2" X 3" rectangles. Place the individual pieces on a platter so they are separated and ready to fry quickly.
Fill a large deep pan with grapeseed oil or neutral frying oil of your choice. The oil should be about 2-3" deep. Bring the oil to 350F and then gently add 5-6 pieces of beignet dough to the oil. Let cook for about 2 minutes on each side or until they puff up and turn golden brown. Flip halfway through for even cooking. Remove them with tongs and set on paper towels to catch the excess oil. Continue the process until all the beignets are cooked.
Add the powdered sugar to a resealable bag and add 2-3 cooked beignets. Seal and shake the bag gently to coat the beignets. Remove and serve immediately!
Buttermilk Beignets are best served immediately and warm.Storage:The dough can keep after rising in the fridge in a tightly sealed container for up to a week.To freeze, cut the dough into the beignet rectangles and freeze individually on a parchment lined baking sheet. Once pieces are frozen transfer to a sealed container for up to a month. Thaw overnight before frying.