Step 1

Bake cake according to box directions in a 9×13 cake pan.

Step 2

Once cake comes out of the oven, poke holes all over the top of the cake.

Step 3

Place sweetened condensed milk and chocolate chips in a microwave safe bowl. Microwave for about 30 seconds to 1 minute.

Step 4

Whisk chocolate and milk until smooth, microwaving more, if needed to melt the chocolate.

Step 5

Pour chocolate mixture over the cake and spread to fill in holes.

Step 6

Set cake aside to cool, about an hour, then refrigerate until completely cooled.

Step 7

To make whipped topping, whip heavy cream until it begins to thicken.

Step 8

Add powdered sugar, cocoa and vanilla extract and whip until stiff peaks form.

Step 9

Spread whipped topping evenly over cooled cake.

Step 10

10.Sprinkle mini chocolate chips over cake and drizzle with chocolate sauce. Refrigerate until ready to serve.