Cream the butter, oil, melted chocolate, and sugar until light and fluffy. Add the eggs one at a time, mixing well after each addition. Stir in the salt, vanilla, and peppermint extract. Gently fold in the cocoa powder and flour until just combined. Refrigerate the dough for one hour. Scoop, roll, and coat in powdered sugar before baking briefly until puffed and crackled.

Instructions

In a large bowl, cream the butter, oil, melted chocolate, and sugar until light and fluffy, about 2–3 minutes.

Add the eggs one at a time, mixing well after each addition.

Stir in the salt, vanilla extract, and peppermint extract until evenly incorporated.

Gently fold in the cocoa powder and flour until the dough has just come together.

Cover and refrigerate the dough for 1 hour to firm up.

Preheat the oven to 350°F and line baking sheets with parchment paper.

Scoop half-ounce portions of dough and roll into smooth balls.

Roll each ball generously in powdered sugar and place on the prepared baking sheets.

Bake for 8 minutes, until puffed and lightly crackled.

If needed, gently flatten hot cookies with the bottom of a drinking glass dipped in powdered sugar.

Let cool briefly on the baking sheet before transferring to a wire rack.