Preheat the oven to 325 degrees F. Spray three 8-inch cake pans with non-stick spray, add parchment and another coat of spray. Set aside.
In a medium size bowl, whisk together the cake flour, baking powder, and salt. Set aside.
In the bowl of a stand mixer fitted with the paddle attachment, beat the butter, canola oil, and sugar on high until fluffy and smooth, about 3 to 5 minutes.
Add the eggs and egg yolks, one at a time to the bowl and beat on medium until well incorporated. The mixture should look smooth and fluffy. This will take another minute or two. Stir in the extracts.
Turn the mixer on low and add 1/3 of the flour mixture to the butter mixture and mix until fully incorporated. Then add half of the sour cream and blend well, followed by another 1/3 of the flour mixture, the second half of the sour cream and lastly, add the remaining flour mixture and mix until incorporated.
Evenly distribute the cake batter among the three pans and bake for 25-30 minutes or until a toothpick inserted into the middle of the cakes comes out clean or with just a few crumbs. Make sure not to over bake.
Remove cakes from the oven and let cool in pans for 10 minutes before inverting onto cooling racks.
Once completely cooled, wrap in plastic wrap and place in the freezer or refrigerator to chill before frosting.