1. Preheat oven to 350°F. Line two baking sheets with parchment paper; set aside.
2. In a large bowl, combine brownie mix, oil and eggs.
3. Drop by level tablespoon full onto prepared baking sheets, keeping 2 inches apart and bake for 12-14 minutes; let cool completely.
4. Place chocolate baking chips into a medium bowl; set aside.
5. In a small saucepan over medium heat, add heavy cream. Bring to just a boil, watching very carefully because if it boils for a few seconds, it will boil out of the pot. Pour over the top of the chocolate baking chips and whisk until smooth. Allow the ganache to cool to the touch.
6. Once cookies are cooled, spread frosting on flat side of one cookie. Top with the second cookie, flat side down to make a sandwich.
7. Spoon 1 tablespoonful of ganache on top of each cookie sandwich and spread to cover top; let sit for 20 minutes before serving. Store in an airtight container in the refrigerator.
Nutrition Information Per Serving
Calories: 375 (Calories from Fat: 180); Total Fat: 20g (Saturated Fat: 8g); Protein: 3g; Total Carbohydrates: 50g (Dietary Fiber: 1g; Sugars: 39g); Cholesterol: 40mg; Sodium: 157mg