Prep: Line two cupcake tins with papers and preheat oven to 350° F.
Make the Cupcakes: In a medium bowl, whisk together the dry ingredients – flour, baking powder, baking soda, and salt. In a large mixing bowl, cream the softened butter for about 30 seconds, until creamy. Add the vegetable oil and beat together for 1 minute. Add the sugar and beat on high speed for 2 full minutes. The mixture will be fluffy. Scrape the sides of the bowl down throughout, to ensure everything is combined. Add the egg whites, two first and then the last one on its own, beating on medium speed between each addition, for 45 seconds. The mixture will be very fluffy. Add the sour cream and vanilla and mix on medium low speed until just combined. Add half of the dry ingredients with the mixer running on low speed. Add the milk with a few streaks of flour remaining, then when the milk is almost mixed in, add the remaining dry ingredients. When just a few streaks of flour remain, turn off the mixer and use a spatula to make sure everything is combined – don't over mix!
Bake: Fill the cupcake liners about ⅔ full. Bake for 13-18 minutes. The tops will be set when lightly touched and a toothpick inserted into the center will come out clean, or with moist crumbs – not wet batter. Let cupcakes cool in the pan a few minutes, thsen let cool completely on a cooling rack. Never frost warm cupcakes – the frosting will completely melt.
Make the Raspberry Frosting: Cream the butter in a large mixing bowl until creamy. Add the powdered sugar, 2 cups at a time, mixing between each addition, adding a splash of heavy cream as needed to help it come together. Add the raspberry preserves, freeze dried raspberries, vanilla, and salt. Beat in the cream cheese last. Taste and add the additional ¼ cup powdered sugar if desired. Frost your cupcakes with a butter knife, offset spatula, or piping bag and tip. Tip: If your frosting is a bit runny or hard to pipe, stick the bowl in the freezer for 5-10 minutes, to help bring it to a stiffer consistency.
Fill & Frost Cupcakes: Use a teaspoon to core out the center of each cupcake and add 1-2 tsp of the raspberry jam filling to each. Pipe frosting on top of each and top with fresh berries.
Serve & Store: Enjoy cupcakes immediately! Store cupcakes in an airtight container in the fridge for 2-3 days.
