Bake the cake according to the package directions until a toothpick comes out clean, about 25 minutes at 350°F (175°C). Let it cool completely.

Crumble the cooled cake into fine crumbs in a large bowl. In a separate bowl, beat the butter and brown sugar until fluffy, then mix in the vanilla, heat-treated flour, and 2 tablespoons milk. Stir in the cake crumbs and mini chocolate chips until the mixture holds together, adding the extra tablespoon of milk if needed.

Roll the mixture into 1-inch balls, insert a lollipop stick halfway into each, and place them on a parchment-lined baking sheet. Freeze for 20 minutes until firm.

Melt the chocolate coating and dip each pop, letting the excess drip off. Set them on parchment or stand them upright in a foam block.

Drizzle with extra melted chocolate or add sprinkles while the coating is still tacky, then let the chocolate set completely at room temperature, about 10 minutes.