Step 1

Preheat the oven to 350 degrees F. Line a 9x13-inch baking dish with parchment paper or cover with pan release.

Step 2

Combine the granulated sugar, brown sugar, vanilla, salt, whole eggs and yolks in a large bowl.

Step 3

Melt the butter and chocolate in a double boiler, then whisk together until fully combined. Whisk in the vegetable oil.

Step 4

Pour the chocolate mixture into the sugar mixture and mix until fully combined. Gently fold in the flour and cocoa.

Step 5

Pour the brownie batter into the prepared pan and bake until a toothpick inserted in the center comes out clean, 30 to 35 minutes.

Step 6

Meanwhile, make the glaze. Place chopped or grated chocolate into a medium-sized, heatproof bowl and set aside.

Step 7

In a large heatproof bowl combine your sweetened condensed milk and butter. Microwave for 30 seconds and stir. Microwave another 30 seconds.

Step 8

When the butter is melted carefully add your chocolate chips and stir in until melted. You can also microwave for 15 seconds more until chips are all melted and ganache is smooth.

Step 9

Pour the ganache over the brownies and immediately sprinkle with the rainbow chips.

Step 10

Let cool completely before slicing.