Preheat your oven to 350°F (175°C).

In a medium bowl, combine fresh raspberries, raspberry jam, granulated sugar, cornstarch, and a splash of lemon juice. Mix thoroughly and set aside.

Cream together the softened unsalted butter, brown sugar, and granulated sugar until light and fluffy, about 2-3 minutes.

Add in the large eggs and vanilla extract, and beat until fully incorporated.

Whisk together the all-purpose flour, unsweetened cocoa powder, baking soda, and salt in a separate bowl. Gradually mix into wet mixture until just combined.

Roll the cookie dough into balls, about 1-2 inches in diameter, creating small indentations.

Spoon a small amount of raspberry filling into the indentation of each cookie.

Place the filled cookie dough balls on a baking sheet lined with parchment paper and bake for 12-15 minutes.

Cool the cookies on the baking sheet for 5 minutes before transferring them to a wire rack.

Melt semi-sweet or dark chocolate and dip the tops of the cookies if desired.

Allow the chocolate-coated cookies to set before serving.