Preheat the oven to 350 F. Line a cupcake tin with liners.
In a small bowl, whisk together the flour, baking powder and salt. Set it aside.
Add the butter to the bowl of an electric mixer and beat it until creamy. Add the sugar and beat with the butter on high speed until fluffy, 2 to 3 minutes. Add in the egg and egg white, mixing well on medium speed until combined. Scrape down the sides of the bowl if needed. Add in the oil and vanilla extract, beating on medium speed for another minute. With the mixer on low speed, add in half of the dry ingredients. Add in the greek yogurt and pour in the milk. Add in the other half of the dry ingredients and mix them on medium speed until the batter is combined.
Use an ice cream scoop to fill the cupcake liners 2/3 of the way full. Bake for 15 to 17 minutes, or until the tops are golden and set. Let cool completely before frosting.
For the frosting:
Add the butter to the bowl of your electric mixer and beat until creamy. Add 2 cups of the powdered sugar, beating until combined. Beat in the raspberries and vanilla extract. At this point, the frosting will look a bit curdled from the water content of the berries. Add the remaining powdered sugar, 1 cup at a time, and beat on medium speed, scraping down the sides and bottom of the bowl as needed. Beat until smooth and creamy.
If the mixture is still a bit curdled, add 1/2 cup more of powdered sugar. Use an icing spatula or a piping bag to frost the cupcakes. You can top each with a raspberry if desired!