• Preheat oven to 350°F.
• Line baking sheets with parchment paper.

For the cookies:

• In a large bowl, mix cake mix, oil, eggs, buttermilk, vanilla, and salt until smooth.
• Dough should be soft but scoopable and hold its shape. If sticky, chill 10 minutes.
• Scoop and shape
• Using a standard cookie scoop (about 1½ tablespoons), scoop dough onto prepared baking sheets, spacing about 2 inches apart.
• Gently flatten each ball slightly with your palm.
• Press the centers
• Use the bottom of a ½ teaspoon measuring spoon or the end of a wooden spoon to press a shallow well into the center of each cookie.
• Bake for 8–10 minutes, until cookies are set but still soft.
• If centers puff up, gently re-press while cookies are still warm.
• Allow cookies to cool completely on the baking sheet before frosting.

For the peppermint icing:

• In a medium bowl, beat butter until smooth.
• Add powdered sugar, cream, peppermint extract, and salt.
• Beat until thick, smooth, and pipeable. Adjust consistency with more cream if needed.

Assemble:

• Pipe or spoon peppermint icing into the center of each cooled cookie.
• Finish with crushed candy canes, sprinkles, or chocolate shavings if desired.