Step 1

Preheat the oven to 400˚F. Line 4 rimmed sheets pans with parchment paper. Line an 8 by 8 inch baking pan with parchment paper creating a paper sling overhang on all 4 sides.

Step 2

Roll out one sheet of the defrosted puff pastry just enough to flatten the seams, then dock with a fork and sprinkle with granulated sugar. Place on one of the prepared baking pans, then top with another sheet of parchment paper and place a second rimmed baking sheet on top.

Step 3

Repeat with a second sheet of puff pastry, then bake both sheets for 25-30 minutes, or until crisp and golden brown. Let cool slightly, then using the prepared 8 inch square baking pan as a guide, cut each sheet into an 8 inch square that will fit inside the prepared pan. Cut one of the 8 inch squares to create 9 squares that you can use to portion out the krémes once set.

Step 4

Place the solid pastry square into the prepared pan and set aside.

Step 5

Place egg whites and a pinch of salt in the bowl of a stand mixer fitted with the whisk attachment. Beat for about 1-2 minutes, or until foamy and bright white, but not yet stiff. Then add ¼ cup sugar gradually and continue to whisk until egg whites reach stiff peaks, about 3-4 more minutes. Set aside.

Step 6

To make the cream filling, add milk and vanilla bean paste to a medium saucepan and heat to a gentle simmer, you want just a few bubbles to form around the edge of the pan.

Step 7

While the milk heats, combine egg yolks, remaining sugar, cornstarch, flour and a pinch of salt in a medium heat-safe bowl. Once milk starts to gently simmer, whisk 1 cup of warm milk into the egg yolk mixture until very smooth. Add egg yolk mixture to the remaining milk mixture on the stove top and cook over medium low heat, stirring constantly, until the cream is very thick and few bubbles form in the center of the pan, about 5-6 minutes. When done, the cream should easily coat the back of a spoon and read about 200˚F on an instant read thermometer. It is important to cook this cream properly and to the appropriate temperature so that the krémes set up properly. Remove from heat and let cool slightly, then whisk in butter one tablespoon at a time until well incorporated.

Step 8

Gently fold the egg whites into the cream mixture in batches until no streaks remain. Once all of the egg whites have been incorporated, add the cream filling to the prepared baking pan, smoothing the cream into an even layer with an offset spatula. Top with the remaining pastry squares, then cover and chill for at least 12 hours, or until set.

Step 9

Using the parchment paper as a sling, remove the krémes from the baking pan and cut into 9 squares with a hot knife, wiping the blade between each cut. Sprinkle the confectioners sugar and serve cold.