Combine the warm water, 1 tbsp of the sugar, and yeast in a large bowl and let sit for 10 minutes.
Stir in the egg and egg white, buttermilk, and vanilla.
In a separate bowl, mix together both flours, remaining sugar, baking powder, and salt.
Pour into the large bowl with the wet mixture and stir with a rubber spatula to combine. {It will be extra sticky}.
Cover the bowl and place in the fridge until the dough has risen and doubled in size, at least 1 hour or up to 2 days if you make in advance.
On a well-floured surface, roll the dough into a large ¼-inch-thick rectangle.
I use a pizza wheel cutter and cut into squares around 2 or 3 inches.
In a large heavy bottomed pot or cast iron skillet, heat a few inches of oil to 350° F {about medium to medium high heat}.
Carefully drop 3-5 beignets to the oil and fry, flipping once, until golden brown. {They cook fast so about 60-90 seconds per side}.
Remove beignets with a slotted spoon to a papertowel lined baking sheet or rack.
Repeat with remaining beignet dough.
While beignets are still hot, sprinkle heavily with powdered sugar.
Serve immediately and prepare to get messy!