For the Cake:
Preheat the oven to 350º F. Prepare two 9-inch cake pans by spraying with baking spray or buttering and lightly flouring.

Add the flour, sugar, cocoa, baking powder, baking soda and salt to a large bowl or the bowl of a stand mixer. Whisk to combine.

Then, add the milk, vegetable oil, eggs, and vanilla to the flour mixture and mix together on medium speed until well combined. Reduce speed and carefully add boiling water to the cake batter until well combined.

Distribute cake batter evenly between the two prepared cake pans. Bake for 30-35 minutes, until a toothpick or cake tester inserted in the center of the chocolate cake comes out clean.

Remove from the oven and allow to cool for about 10 minutes, remove from the pan and cool completely.

For the Frosting:
Beat together the brown sugar and butter on medium speed in your electric mixer, until creamy. Add the flour, vanilla and salt into the butter-sugar mixture, until well combined. With the mixer on low speed, add in the milk, little by little, until fully incorporated. Then, fold in the chocolate chips. When the cake has cooled (feel free to pop it into the fridge for a little while), spread frosting on the top of each layer, and around the outside of the cake.

For the Ganache:
Heat the heavy cream in a small pot over medium heat. When the cream is heated, remove from the stove and add in the dark chocolate. Whisk with a fork until fully melted and the ganache has a smooth and shiny texture. Pour over the top of the cake, letting the ganache drip down the sides.

Decorate the top of the cake with any additional frosting and mini chocolate chip cookies, if desired.