01 - Dissolve yeast in warm water with a pinch of sugar in a large bowl. Let stand 5 minutes until foamy.
02 - Stir in remaining sugar, milk, egg, and salt. Add 2 cups flour and mix until combined.
03 - Add melted butter, then gradually mix in remaining flour until a soft dough forms.
04 - Turn dough onto a floured surface and knead 5 to 7 minutes until smooth and elastic.
05 - Place dough in a greased bowl, cover, and let rise in a warm spot until doubled, about 1 hour.
06 - Roll dough on a floured surface to 1/2-inch thickness. Cut into 2-inch squares.
07 - Heat 2 inches of vegetable oil in a deep pot to 350°F.
08 - Fry in batches without crowding for 1 to 2 minutes per side until puffed and golden brown.
09 - Remove with a slotted spoon, drain on paper towels, and dust generously with powdered sugar while warm.
10 - Warm cream and butter in a small saucepan over low heat. Add chocolate and stir until melted and smooth. Remove from heat and stir in vanilla and salt.
11 - Serve beignets warm with chocolate sauce for dipping.