In a large mixing bowl, cream the butter and sugar together until light and fluffy, about 2 minutes with a hand mixer.

Add the egg yolk and vanilla extract, mixing until fully combined.

In a separate bowl, whisk together the flour, cocoa powder, and salt.

Gradually add the dry ingredients to the wet ingredients, stirring until a soft dough forms.

If the dough is too sticky, chill it in the refrigerator for 15 minutes before shaping.

Preheat the oven to 350°F (175°C). Line a baking sheet with parchment paper.

Scoop out small portions of dough and roll them into 1-inch balls.

Place them on the prepared baking sheet, spacing them about 2 inches apart.

Use your thumb or the back of a teaspoon to gently press an indentation into the center of each dough ball.

Bake for 8-10 minutes, until the edges look set but the centers remain slightly soft.

Let the cookies rest on the baking sheet for a few minutes before transferring them to a wire rack to cool completely.

While the cookies cool, melt the chocolate and coconut oil together.

Place the chopped chocolate and coconut oil in a heatproof bowl and microwave in 20-second intervals, stirring between each, until smooth.

Dip each cookie completely into the melted chocolate, allowing the excess to drip off before placing them back onto parchment paper.

Let the chocolate set at room temperature or refrigerate for faster setting.

Once the chocolate is firm, spoon a small amount of cherry pie filling into the indentation of each cookie.

If using maraschino cherries, press one into the center, allowing the juices to lightly coat the surrounding chocolate.