To Make the Cupcakes:

Preheat the oven to 350° and line 12 muffin cups with paper liners.

In the bowl of a stand mixer, combine all of the dry ingredients.  Add the butter and, using the whisk attachment, beat until the mixture resembles soft sand and there are no large chunks of butter left.  If the butter is very soft, the mixture may become a paste, which is fine.

Add the egg whites one at a time, and beat well after each addition.  With the mixer running on low, slowly add in the milk and extracts until well incorporated.  Scrape the bowl with a rubber spatula, then beat the batter for 2 minutes on medium speed.

Divide the batter between the 12 muffin tins, then bake for 18-20 minutes, or until the tops spring back when you tap them gently.  Remove them and let cool completely before frosting.

To Make the Frosting:

In a medium mixing bowl, beat together the softened butter and the creme fraiche with an electric hand mixer. It may look slightly curdled, but will smooth out. Add in the powdered sugar 1-2 cups at a time and mix it in on low speed to avoid and explosion of powdered sugar. Add until it reached a pipable consistency–it will still be soft.

Fit a piping bag with a large star tip and fill it with the frosting. Set aside (in the refrigerator if your kitchen is hot) until ready to pipe the frosting on.

To Make the Drizzle:

Place the blueberry preserves in a small saucepan. Mix the cornstarch into the water, then stir it into the preserves. Cook them over medium low heat, stirring constantly until the mixture has bubbled and thickened. Set aside and let it cool.

To Assemble the Cupcakes:

Cut a circle in the top of the cupcakes, about an inch across and about 2/3 down into the cupcakes. Fill with about 2 tsp. of the blueberry preserves, then pipe the 2-3 swirls of the frosting over the top. Put the frosted cupcakes in the freezer for about 10 minutes, then drizzle some of the cooled topping over the top of each.

Store in the refrigerator until serving, then let come to room temperature.