Prepare the vanilla custard: Whisk together egg yolks, granulated sugar, and cornstarch in a medium bowl. In a saucepan, heat the whole milk until small bubbles form around the edges. Slowly pour the hot milk into the egg mixture while whisking constantly. Return the mixture to the saucepan and cook over medium heat, stirring constantly, until the custard thickens. Remove from the heat and immediately stir in the vanilla extract. Transfer to a clean bowl, cover the surface directly with plastic wrap touching the surface, and chill in the refrigerator until fully set.

Preheat oven to 375°F (190°C). Grease a 12-hole muffin tin with butter or non-stick spray.

Form the cruffins: On a lightly floured surface, unroll the pastry dough sheets and combine edges to form one large, seamless rectangle. Brush lightly with melted butter and sprinkle with sugar. Cut into 12 even squares.

Stack, roll, and coil: Stack three squares of dough. Gently roll up each stack. Cut the rolled log lengthways in half to expose the internal layers. Coil each half into a muffin shape and place it in the prepared muffin tin cup. Repeat for the rest of the dough.

Bake the cruffins: Bake for 20-25 minutes until puffed and a spectacular golden brown. Let cool in the pan for 5 minutes, then transfer to a wire rack to cool completely.

Fill the cruffins: Once completely cool, use a small, sharp knife or a straw to create a hole in the bottom center of each cruffin. Fill a piping bag with the chilled custard and pipe it into each cruffin until full.

Prepare the chocolate glaze: In a microwave-safe bowl, combine the 3/4 cup semi-sweet chocolate chips and 1 tablespoon butter. Microwave in 15-second intervals, stirring in between, until melted and smooth.

Finish and serve: Take each filled cruffin and gently dip the top into the melted chocolate glaze. Place on a plate or rack to set. Finely sift the powdered sugar over the tops. Garnish the plate and a linen napkin with additional semi-sweet chocolate chips, just like in image_5.png. Serve immediately with a coffee.