Preheat the oven to 350°F. Like three 6-inch cake pans with parchment paper.
To make the batter: In a large mixing bowl, add the canola oil, cane sugar, heavy whipping cream, vanilla extract, and eggs. Whisk together.
Add the cake flour, baking powder, and salt. Mix together until combined into a smooth cake batter. Add in the mini chocolate chips and stir to combine completely.
Divide batter evenly into each cake pan, weighing about 430 grams each. Spread evenly.
Bake for 30 to 35 minutes or until a toothpick inserted in the center comes out clean. Allow to cool completely in the cake pans.
To make the frosting: In the bowl of a stand mixer fitted with the paddle attachment, add the butter, light brown sugar, vanilla extract, and powdered sugar. Mix on low until combined then speed mixer up to high and mix for 1 to 2 minutes or until light and fluffy. Add in 1 to 2 tablespoons of milk as needed.
Transfer the frosting to a piping bag with Ateco tip #827.
On a cake stand or spinner, place the first cake layer (I like to do this bottom side down so it's flush with the cake plate).
Starting outer edge of the cake, pipe a spiral of frosting into the center of the cake.
Place the second cake layer on top (do this one bottom side up, as this helps the cake look straight). Pipe a spiral of buttercream frosting on top, and repeat this process with the second and third cake layer (bottom side up).
Add mini chocolate chips on top of the cake for garnish!
Store in a cake dome for up to 3 days.