For the cupcakes, preheat oven to 350ºF. Line 24 muffin cups with cupcake liners and coat lightly with non-stick cooking spray. If making a layered cake, grease four cake pans.
In a small bowl, combine flour, baking powder and salt. Set aside.
Using an electric mixer, cream butter and sugar on medium speed until light and fluffy. Beat in egg whites and full egg one at a time, until well combined. Mix in vanilla extract.
On low speed, alternate adding flour mixture with the milk and raspberry iced tea, beginning and ending with the flour. Mix just until combined.
For cupcakes: Fill cupcake pans halfway with cupcake batter. Place 1 teaspoon of raspberry jam in the middle of the batter and top each cupcake with more batter, filling tin ¾ full. Bake 20-22 minutes, until slightly golden and cooked through. Cool completely before frosting.
For layered cake: Evenly distribute batter among the four cake pans. Bake for 26 – 28 minutes.
White Chocolate Frosting
Using an electric mixer, cream together butter and icing sugar on low speed until well combined.
Add melted white chocolate and milk, mixing until smooth and desired spreading consistency.
To Assemble
For cupcakes: Frost cooled cupcakes and drizzle seedless raspberry jam over the frosting, topping with white chocolate curls.
For layered cake: Place one cake layer down on cake stand/plate. Top with frosting and then spread a thin layer of raspberry jam on top of the frosting. Place second cake layer on top and repeat.
Frost the tops and sides of cake. Smooth out frosting with offset spatula or bench scraper.
Garnish with fresh raspberries, chocolate curls, and flowers of choice.