Directions

1. For the berry jam, put half the berries in a medium saucepan and use a potato masher to crush them. Add the remaining berries, sugar, and lemon juice, and stir with a heat-proof rubber spatula. Cook over medium-low heat for a few minutes until the sugar dissolves, stirring occasionally. Increase the heat to medium and cook, stirring frequently, until the mixture begins to thicken, about 15 minutes. It may bubble up, reduce the heat a bit if needed. Use the spatula to scrape the bottom and sides as you stir to avoid sticking. Taste the jam and adjust with more lemon juice or sugar if needed. Continue to cook until the jam is thick and shiny, about 5 minutes longer. Transfer to a bowl and let cool, then cover and refrigerate until needed.
2. For the pastry cream, combine the milk and bay leaves in a small saucepan and bring to a simmer over medium heat. Set aside to steep, covered, for 30 minutes. Remove the bay leaves and set the pan over medium heat. Add half of the sugar and stir until dissolved. Take the pan from the heat.
3. Put the egg yolks in a medium bowl. In a small bowl, whisk together the remaining sugar, cornstarch, and salt. Add this to the egg yolks and whisk to blend. Whisk about one quarter of the warm milk into the egg yolk mixture until smooth, then gradually add this to the saucepan, whisking constantly. Cook over medium-low heat, whisking constantly, until the mixture just comes to a boil and begins to thicken, 3 to 5 minutes. Reduce the heat to low and keep whisking for 2 minutes. Take the pan from the heat and whisk in the butter pieces until smooth. Transfer to a bowl, lay plastic wrap directly on the surface of the pastry cream, and set aside to cool. When cool, refrigerate until needed.
4. Preheat the oven to 375 F. Line a baking sheet with a silicone baking mat or parchment paper.
5. Cut the puff pastry dough into 4-inch squares (see below). From each corner on the squares, make a slit about 1 1/2 inches long toward the center. Fold one of the corner points down nearly to the center and press gently to adhere. Fold the same side of the other corners down in the same way, creating a pinwheel.
6. Set the pinwheels on the baking sheet (bake in 2 batches if needed) and use your fingertips to press the centers a bit thinner. Combine the egg and water in a small dish, blend well with a fork, and brush this lightly on the pastries. Add a generous 1 tablespoon of pastry cream to the center of each pinwheel. Bake for 10 minutes, then lower the oven temperature to 325 F and bake until the pastry is well browned, 35 to 40 minutes longer. Transfer to a wire rack to cool.
7. To serve, spoon a generous teaspoon of jam over the pastry cream. Top the jam with fresh berries and edible flowers, then finish with a light dusting of powdered sugar.