In a bowl, mix 1/2 cup all-purpose flour, 1/2 cup brown sugar, and 1/4 cup softened unsalted butter until you have a smooth dough.

Place the dough between two sheets of parchment paper and roll it out to about 1/8 inch thick.

Refrigerate the rolled-out dough for about 30 minutes until firm.

In a saucepan, combine 1 cup water and 1/2 cup cubed unsalted butter. Heat over medium until melted and boiling.

Quickly stir in 1 cup all-purpose flour and 1/4 teaspoon salt until the mixture comes together. Return to low heat for 2-3 minutes until the dough forms a ball and pulls away from the pan.

Transfer the warm dough to a mixing bowl. Allow it to cool slightly, then add 4 large eggs one at a time, mixing well after each until the dough is smooth and glossy.

Preheat your oven to 375°F (190°C).

Spoon the choux pastry into a piping bag fitted with a round tip. Pipe small mounds (about 1.5 inches in diameter) onto a baking sheet lined with parchment paper.

Remove the chilled craquelin from the refrigerator. Cut into circles slightly smaller than your choux mounds and place them on top.

Bake in the preheated oven for 25-30 minutes or until golden brown and puffed.

In a mixing bowl, whip 1 cup heavy cream until soft peaks form. Gradually add 1/4 cup powdered sugar and 1 teaspoon vanilla extract until stiff peaks form.

Gently fold in 1 cup mashed fresh raspberries. If using, dissolve 1 tablespoon gelatin in warm water and mix it in for stability.

Once baked, remove the choux pastries from the oven and allow them to cool completely.

Using a small knife, make a hole in the bottom of each cooled choux. Fill a piping bag with the raspberry cream and pipe it into each pastry until full.

Arrange the filled choux on a serving platter and enjoy each delightful bite of this Raspberry Choux au Craquelin!