In a microwave safe bowl, microwave your flour for 60-90 seconds, stirring every 30 seconds. Set aside to cool completely.
In a medium mixing bowl, cream together ½ cup (1 stick) softened butter and brown sugar. Once smooth, mix in ¼ cup milk and vanilla extract.
Sprinkle in the heat-treated flour and mix to form a dough, then fold in ½ cup of mini chocolate chips. Cover and transfer to the freezer for 30-45 minutes to firm up.
Heat-treat your brownie mix by pouring it into a microwave safe bowl and microwaving for 60-90 seconds, stirring every 30 seconds, or until it reaches 160 degrees F.
Combine your heat-treated brownie mix with ½ cup softened butter (1 stick) and ¼ cup milk. Mix to form a batter consistency, then cover and transfer to the freezer for 30-45 minutes to firm up.
Line a baking sheet with parchment paper or a silicone baking mat, then roll the cookie dough into 2 tsp balls, then do the same with the brownie batter, placing them on the baking sheet as you go.
Sandwich one ball of cookie dough with one ball of brownie batter, then roll the two together to form one truffle. If they seem soft, return to the freezer for 15 minutes.
In a microwave safe bowl, combine semi-sweet chocolate chips and vegetable oil. Microwave in 30 second intervals, stirring in-between, until melted and smooth.
Working one by one, coat each cookie dough brownie bite in melted chocolate, let any excess chocolate drip off, then return to the prepared baking sheet.
Immediately sprinkle with the remaining mini chocolate chips, then let the chocolate coating set completely before enjoying!