Preheat your oven to 350 degrees F. Line a cupcake tray with cupcake liners. Set aside.
Into the bowl of an electric mixer with the paddle attachment, beat butter and oil together for 3-4 minutes until they are unified.
Add brown sugar into the mixture and beat on medium to high speed until light and fluffy. Scrape down the sides of the bowl.
With the mixer on low speed add eggs in one at a time followed by the vanilla strawberries and milk. Beat on to combine.
While your mixture is mixing, sift flour, baking powder, and salt into a medium bowl.
With the mixer on low speed, add in the flour mixture into the bowl and mix until just combined. Scrape down the bowl and mix for just 15 seconds more. Do not over mix or your cupcakes will become quite dense.
Distribute cupcake batter evenly between cupcake tin.
Bake for 18 minutes, or until knife comes out clean. Each oven is slightly different, so I suggest keeping a close eye on your cupcakes -- without opening the oven. Use your oven light!