1. In a large mixing bowl, cream together the softened butter, peanut butter, granulated sugar, and brown sugar until light and fluffy. Add in the egg and vanilla extract and mix well until combined.

2. In a separate bowl, whisk together the flour, baking soda, baking powder, and salt. Slowly add the dry mixture to the wet ingredients, stirring until a soft dough forms.

3. Preheat the oven to 350°F (175°C). Line a baking sheet with parchment paper. Scoop out tablespoon-sized balls of dough and place them 2 inches apart. Bake for 10-12 minutes. Let them cool on the baking sheet for 5 minutes before transferring to a wire rack.

4. While cookies are cooling, cut each marshmallow in half widthwise. Place cut side down on a microwave-safe plate. Microwave for 5-8 seconds until puffed but not melted. Place one marshmallow on each cookie.

5. Melt white chocolate or candy melts according to package instructions. Spoon a generous amount over each marshmallow, letting it drip for a melted effect.

6. Decorate using black gel or melted chocolate for eyes, smile, and buttons. Add orange gel for the nose. Use candy eyes or sprinkles for extra personality.

7. Let the cookies sit at room temperature or refrigerate until the topping and decorations are completely set.