Two days before, prepare the Champagne Chocolate Ganache by tempering egg yolks with hot cream and champagne, then whisking in cocoa paste and pouring over dark chocolate.

Make the pastry dough by mixing flour, salt, sugar, yeast, water, egg white, butter, and cream in a stand mixer until just combined; proof for 2-3 hours until doubled.

Punch down the dough, shape into a 10-inch square on parchment, and refrigerate overnight along with a prepared 7-inch butter block.

Laminate the dough by placing the butter block in the center of the dough square, folding corners over to seal, and rolling into a 20-inch square before folding back to a 10-inch square.

Repeat the rolling and folding process after 1 hour of chilling, then refrigerate the laminated dough overnight.

On the final day, roll the dough to 1/2 inch thickness, cut into donut shapes, and proof for 2 hours until tripled in size.

Fry the pastries in 350°F grapeseed oil for 90 seconds per side until golden brown, then drain on paper towels.

Inject the cooled pastries with whipped ganache, roll the edges in vanilla sugar, and pipe a ring of chocolate glaze on top.