Heat oven to 350°F. In a large bowl, mix softened butter and sugar until smooth. Add eggs and vanilla; beat well.
In a separate bowl, whisk together flour, cocoa, baking powder, baking soda, and salt. Slowly add this dry mix to the butter mixture, stirring until a soft dough forms.
Roll dough into 1½-inch balls and place them 3 inches apart on greased baking sheets.
Push a lollipop stick into the center of each ball, then flatten each cookie slightly using a glass dipped in sugar.
Bake for 10–12 minutes, until set. Let cookies cool on the baking sheets for a few minutes, then transfer to a wire rack to cool completely.
Tint the vanilla frosting with food coloring, then spread it over each cooled cookie. Use decorating gels and optional candies to make fun Halloween faces.
Notes
Nutrition per serving: Calories: 207, Total Carbs: 31g, Net Carbs: 30g (1g fiber), Fats: 9g, Protein: 3g.