Preheat the oven to 350 and prepare a cupcake baking dish by lining with 24 papers.
In a mixing bowl, sift together flour, baking powder, and salt.
In a large mixing bowl, cream butter and sugar until light and fluffy. Add the whites, beating them in one at a time.
Work in the flour in batches, alternating with the milk. Then, fold in the raspberry jam.
Divide the batter among the cupcake papers and bake until they pass the toothpick test, about 18 minutes.
Let rest in the baking dish for 5 minutes, then transfer to a wire rack to cool the rest of the way.
Whipped Peanut Butter Frosting
Cream the butter and peanut butter until fluffy.
Mix in about 1 cup of powdered sugar, then add 1 to 2 tbs milk. Mix in the remaining powdered sugar, then test the taste and texture. Add more milk or more powdered sugar as needed for desired creaminess.
Assemble the cupcakes
Using a teaspoon, scoop a small circle of cake from the top of each cupcake.
Fill that hole with 1/2 to 1 tsp raspberry jam.
Using a piping bag, offset spatula, or even a butter knife, spread on the peanut butter icing.