Put the ROLOs in the freezer for at least 6 hours.
Sift the flour with the cocoa powder and baking powder, and set aside.
In a large bowl, cream the butter with the brown sugar, then mix in the vanilla extract and egg until smooth.
Combine the dry ingredients with the wet ingredients until well mixed. Let the dough rest for 30 minutes.

Preheat the oven to 350°F (180°C).
Roll 1 tablespoon (15ml) of dough into a ball and place a ROLO in the center, covering it evenly with dough.
Place the balls onto a baking sheet lined with a silicone mat, leaving 2″ (5cm) of space between each cookie.
Flatten each ball of dough into a circle of 2″ (5cm). Make sure the dough is well sealed and there are no cracks.

Bake in the center of the oven for about 8 minutes, or until they are dry to the touch. Transfer to a wire rack to cool.