Step 1: Preheat the Oven and Prepare Puff Pastry

Begin by preheating your oven to 425°F (218°C). If you’re using frozen puff pastry, ensure that it has thawed according to the packaging instructions, leaving it cold but manageable. You should be able to work with it without it becoming too soft. If you’re using refrigerated puff pastry, skip the thawing step and proceed to rolling. Use a rolling pin to gently flatten the sheets slightly to make them easier to work with.

Step 2: Cut the Puff Pastry

Once your puff pastry is ready, cut each sheet into four equal squares. You should end up with eight squares, each measuring around 5 inches on each side. Feel free to cut the squares smaller if you’d like, but be aware that smaller squares may require adjusted baking times.

Step 3: Egg Wash and Shape Croissants

Brush each square of puff pastry with an egg wash, which will give your croissants a beautiful golden color as they bake. Then, take one corner of each square and fold it over into a triangle shape, pressing the edges firmly to seal them. This will help the croissants keep their shape during baking and prevent them from opening up in the oven. Brush the top of each croissant with more egg wash, and if desired, sprinkle a little coarse sugar on top for added texture and sweetness.

Step 4: Bake the Croissants

Place the croissants on a baking sheet and bake them in the preheated oven for 22-25 minutes, or until they’re deep golden brown and fully puffed. Keep an eye on them during the last few minutes of baking, especially if you’re using frozen puff pastry, as it may need a few extra minutes to bake. The croissants should be crispy on the outside and soft and flaky on the inside. Once baked, set them aside to cool completely. Don’t cut into them just yet; they need to cool for the best results.

Step 5: Make the Berry Jam

While the croissants are baking, it’s time to make the homemade berry jam. In a medium saucepan, add the frozen blueberries, sugar, and lemon juice. Place the pan over medium heat and bring the mixture to a simmer. Stir the jam occasionally and allow it to cook for 15-20 minutes until the berries have broken down and the mixture has thickened. Keep an eye on it to ensure it doesn’t burn, and stir frequently. Once the jam has reached a thick consistency, remove it from the heat and set it aside to cool. If you’re using fresh berries, you’ll need to cook the jam for an additional 5 minutes to help reduce the moisture content and reach the desired thickness.

Step 6: Prepare the Cream Filling

While the croissants and jam are cooling, prepare the creamy filling. In a large mixing bowl, pour in the cold heavy whipping cream, powdered sugar, and vanilla extract. Use a hand mixer to beat the mixture until stiff peaks form. In a separate bowl, combine the softened cream cheese and sour cream. Beat these together for 1-2 minutes until smooth, fluffy, and well-combined. Once the cream cheese mixture is ready, gently fold in the whipped cream, one-third at a time, until the two mixtures are fully incorporated. Taste the filling and adjust the sweetness by adding more powdered sugar if desired. If you’re making the filling ahead of time, store it in an airtight container in the refrigerator, but bring it to room temperature before using and re-whip it to restore its fluffy texture.

Step 7: Assemble the Croissants

Once the croissants have cooled completely, use a sharp knife to carefully cut each one in half, but be sure not to cut all the way through. You want to create a pocket that you can fill with the jam and cream. Spread a generous amount of the berry jam on both halves of the croissants. Don’t be afraid to pile it on; the jam is the highlight of this dessert. Next, add a heaping spoonful of the cream filling, making sure to fill each croissant generously. The cream filling is rich and fluffy, and you’ll want to enjoy every bite of it. Once filled, gently press the croissants back together.

Step 8: Dust with Powdered Sugar and Serve

To finish, dust the tops of the croissants with powdered sugar for a beautiful, polished look. These croissants are best served immediately while the pastry is still crisp and fresh. The combination of the flaky croissant, sweet berry jam, and creamy filling is sure to impress anyone who takes a bite.