Preheat your oven to 325 Degrees F
With a handheld or stand mixer with a paddle attachment, whip your butter & shortening together until smooth.
Now add your maple syrup & mix until butter and shortening are well incorporated, making sure to scrape down the inside of your bowl.
Now add your egg yolks, egg, flour, baking powder, salt and milk, and mix all together until just incorporated, make sure not to over mix your batter.
Now place your batter in your cupcake liners and bake for 20 minutes, every oven is different so make sure to check your cupcakes by lightly touching and if they spring back to the touch then they're ready.
Let cool completely before frosting your cupcakes and enjoy!!!