Preheat the oven to 350˚F (180˚C). Line a muffin pan with 12 paper liners.
In a large bowl, sift together the flour, baking powder and salt.
In a medium bowl, whisk the milk and egg whites together until blended.
In a large mixing bowl with an electric mixer fitted with a paddle attachment, add the sugar and lemon zest. Mix on low speed for 1 minute. Add the butter and beat on medium speed for 3 minutes or until light and fluffy. Add the extract and beat until blended. Add 1/3 of the dry ingredients. Mix on low speed until just combined. Scrape down the bowl and add ½ wet ingredients and beat. Mix in ½ of the remaining dry ingredients. Scrape down the bowl again. Add the rest of the milk mixture and beat until combined. Mix in the rest of the dry ingredients. Beat on medium speed for 2 minutes.
Divide the batter evenly among the cupcake liners, about 2/3 filled. Bake in the oven for 18 – 22 minutes. Test the cupcakes with a toothpick for doneness. The toothpick should come out clean. Remove from oven and cool in the pan for 5 minutes. Transfer the cupcakes to a cooling rack and cool completely.
In a small saucepan over medium-low heat, add raspberries and sprinkle the sugar on top. Cook for about 5 – 7 minutes until raspberries are broken down, using a spatula to help. Strain the sauce through a fine mesh sieve to a small bowl. Cool completely.
In a large mixing bowl with an electric mixer fitted with a paddle attachment, beat the butter and shortening until light and fluffy. Add the vanilla extract and 2 tablespoons raspberry sauce. Beat until blended. Add half of the sugar and mix on low speed until combined. Add the rest of the sugar and mix well. Scrape the bowl a few times if needed. Mix in 1 tablespoon cold milk. Check the consistency. If the frosting is too thin, add a little more powdered sugar. If the frosting is too stiff, add more cold milk by adding 1 tablespoon at a time. Frost and decorate the cupcakes. Top with a fresh raspberry.