In a medium bowl, combine fresh raspberries, raspberry jam, cornstarch, and lemon juice. Gently mash the raspberries with a fork while mixing, ensuring a well-blended filling. Set aside.

In a large mixing bowl, cream together softened unsalted butter, granulated sugar, and brown sugar until light and fluffy, about 3–4 minutes. Beat in eggs and vanilla until fully combined.

In another bowl, whisk together all-purpose flour, unsweetened cocoa powder, baking soda, and salt. Gradually add to the wet ingredients, mixing until just combined.

Using a cookie scoop, take a portion of dough, flatten it, spoon in raspberry filling, and seal it into a ball. Repeat with remaining dough and filling.

Preheat oven to 350°F (175°C). Arrange cookie balls on a lined baking sheet and bake for 10–12 minutes, until edges are set but centers remain soft.

Allow cookies to cool for 5 minutes. Melt chocolate with coconut oil until smooth, dip cookies, and let set on wire rack.