In a large mixing bowl, combine the melted butter, brown sugar, and granulated sugar. Use a spatula or whisk to mix until smooth and well combined. Add in the egg and the egg yolk, then mix again until fully incorporated. Stir in the heavy cream and vanilla extract.

Add in flour, cocoa powder, baking soda, and salt. Stir until no streaks of flour remain. Fold in the chocolate chips until evenly distributed.

Using a 1.5 to 2 tablespoon cookie scoop, portion out the dough and place the scoops onto a parchment-lined plate or tray. Cover and chill the dough balls in the refrigerator for at least 2 hours or up to overnight. This step is important to help the cookies hold their shape and develop a richer flavor.

While the cookie dough is chilling, prepare the cherry filling. In a medium saucepan, combine the water, granulated sugar, lemon zest, vanilla extract, and cornstarch. Stir to dissolve the cornstarch completely.

Add the pitted and halved cherries to the pan and place over medium heat. Stir continuously as the mixture begins to simmer. As the cherries soften, gently press them with the back of your spatula or spoon to break them down and release their juices. Continue cooking for about 5–6 minutes, or until the mixture thickens into a jammy compote.

Once thickened, remove from heat and transfer the compote to a bowl. Let it cool to room temperature, then chill in the refrigerator until you're ready to assemble the cookies.

Preheat your oven to 180°C (350°F). Line a baking sheet with parchment paper and arrange the chilled cookie dough balls on it, spacing them 1.5 to 2 inches apart to allow for spreading.

Bake the cookies for 13 to 14 minutes, or until the edges look set and the centers still look slightly soft. Remove the tray from the oven and, while the cookies are still hot, use the back of a tablespoon to gently press an indentation into the center of each cookie. This will make space for the cherry compote later.

Allow the cookies to cool on the baking tray for about 10 minutes, then transfer them to a wire rack to cool completely.

In a medium bowl, pour in the cold heavy cream and add the powdered sugar. Using an electric hand mixer or a stand mixer fitted with the whisk attachment, beat the cream on medium-high speed until stiff peaks form. Be careful not to over-whip, or the cream may become grainy

Once the cookies have cooled and the cherry compote is chilled, it’s time to assemble. Spoon about 1 heaping teaspoon of cherry compote into the center indentation of each cookie. Then, top with ½ to 1 tablespoon of whipped cream frosting. Use the back of a spoon or an offset spatula to gently spread the whipped cream on top of the cherry layer.

Finish each cookie with a sprinkle of chocolate shavings for that classic Black Forest cake look. If you like, top with a whole or half a cherry for a cute, bakery-style presentation.