In a large bowl, cream the butter and sugar until light and fluffy, about 2 minutes. Beat in the egg and vanilla just until combined.

In a separate bowl, whisk the flour, baking powder, and salt. Gradually add to the butter mixture, mixing on low until a dough forms.

Divide the dough in half, flatten into disks, wrap, and chill for at least 30 minutes.

Preheat the oven to 350°F (175°C). On a floured surface, roll one disk to 1/4-inch thickness. Cut into circles and place 1 inch apart on parchment-lined baking sheets.

Bake for 8–10 minutes, until the edges are barely golden. Cool on the sheet for 5 minutes, then transfer to a wire rack to cool completely.

Use a dab of chocolate to attach two pretzel twists as antlers. Press two candy eyes and a red M&M into place. Draw a mouth with melted chocolate. Let set before serving.