01 -
Combine both flours, yeast, sugar, and salt in the bowl of a stand mixer. Add egg whites and milk, then mix with the dough hook until a rough dough forms. Add the softened butter a little at a time and knead 6-8 minutes, until smooth and elastic.
02 -
Place the dough in a lightly greased bowl, cover, and let rise until doubled, about 90 minutes. Press out the air, shape into a flat rectangle, wrap, and chill at least 2 hours or overnight.
03 -
Roll the chilled dough into a long rectangle on a floured surface. Spread the cool, soft butter evenly over the dough, fold into thirds, wrap, and chill 30 minutes. Roll and fold into thirds 3 more times, chilling 20-30 minutes between turns.
04 -
For the jam, simmer strawberries, sugar, and lemon juice for 8-10 minutes, until thick and glossy. Chill. For the pastry cream, heat the milk, whisk sugar, egg yolk, egg, flour, and cornstarch in a bowl, temper with hot milk, then cook until thick. Stir in vanilla bean paste and butter, cover the surface, and chill.
05 -
Roll the laminated dough to about 1/2 inch thick. Cut 8 rings with a 3 1/2 inch cutter and a smaller center cutter. Place on parchment, cover loosely, and proof until puffy, about 75-90 minutes. Chill 20 minutes before frying for easier handling.
06 -
Heat oil in a heavy pot to 350°F. Fry 1-2 cronuts at a time for 2-3 minutes per side, until deep golden and cooked through. Drain on a rack or paper towels.
07 -
Mix the granulated sugar with the freeze-dried strawberry powder. Roll the warm cronuts in the strawberry sugar. Once just warm, pipe vanilla bean pastry cream and strawberry jam into each pastry from several points, then top with a small spoonful of cream and sliced strawberries.