Preheat the oven to 350 degrees. Grease and flour three 8-inch round cake pans.

In a bowl or liquid measuring cup, whisk together the milk, egg whites, and vanilla. Set aside.

In the bowl of a stand mixer fitted with the paddle attachment, place the flour, sugar, baking powder, and salt. Stir on low speed to just until combined.

Increase the speed to medium and add in the softened butter - a few pieces at a time. Continue to mix until the butter pieces are the size of small peas.

Pour in half of the milk mixture and mix on medium-high until light and fluffy, about 1 minute.

Stop the mixer and scrape down the bowl. With the mixer on low, stream in the remaining milk mixture. Mix on medium-low no longer than about 30 seconds or until incorporated.

Evenly distribute the batter between the prepared pans. Bake for 22 to 25 minutes, or until a toothpick inserted into the center of the cakes comes out clean.

Place the cake pans on a wire rack and let cool for about 10 minutes. Remove the cakes from their pans and continue to cool completely on a wire rack before filling and frosting.

In the bowl of a stand mixer fitted with the paddle attachment, beat the butter and sugar on medium-high speed until light and fluffy, about 3 minutes.

Stop the mixer and scrape down the bowl. With the mixer on medium, add the cream cheese, a couple pieces at a time, and mix until smooth.

Add the vanilla and the strained jam. Mix until combined.

Place one layer of cake on a cake board or serving dish. Spread about half of the blueberry jam on top with an offset spatula, leaving a small margin around the edges.

Top with the next layer of cake and repeat with the remaining jam.

Place the last layer of cake on top. Crumb coat the cake with the frosting and set in the refrigerator to chill for about 15 minutes.