For the Cupcakes:
3/4 cup cake flour
1/2 teaspoon baking powder
1/8 teaspoon salt
1 teaspoon lemon zest
1 tablespoon poppy seeds
5 large eggs at room temperature
1 teaspoon vanilla
7 oz almond paste at room temperature
1 cup sugar
8 oz room temperature butter, cut into small chunks
For the Filling:
2 pints blueberries
sugar to taste plus some to coat the berries
1/4 teaspoon lemon zest
1 cup mascarpone
1 1/2 cups cream
1 pint redcurrants
1 egg white
Position rack in lower third of the oven. Preheat to 350°F. Line two muffin trays with paper cups.
Sift the flour, baking powder and salt together on to a sheet of waxed paper. In a small bowl combine the eggs and vanilla. In the mixer, using the paddle attachment, beat the almond paste on low speed until it breaks up. Slowly add the sugar, beating until it is incorporated. Add the butter a little at a time to the mixing bowl. Turn up the speed to medium and continue beating until the butter is light and fluffy.
With the mixer still on medium, pour in the eggs in a very slow and steady stream. Stop the mixer and scrape down the sides and then continue to beat for another 30 seconds. Add the lemon zest and the poppy seeds. Then stir in the flour using a wooden spoon. Do not over mix. Spoon the batter into the prepared muffin tins and bake in the oven for 20-25 minutes, until the center springs back when touched lightly and it is a nice deep golden brown.
Meanwhile, place all but 1 cup of the blueberries in a small pan with some sugar and lemon zest until the berries pop and are soft. Allow to cool. Taste and add more sugar if necessary. Whisk the mascarpone until smooth, slowly add in the cream. Then whisk until thick but not grainy looking. If you over-whip it you can always add a little more cream. Put in a piping bag, fitted with a large piping a large rose tip.
Whip the egg white until it is liquid. With a clean pastry brush, brush the remaining bblueerries and the redcurrants with the egg white and then roll in some sugar. Allow to dry on a cooling rack for a half hour or until dry.
Cut a circle out of the top of each cupcake. Fill with the cooked blueberries. Pipe a big swirl of the mascarpone cream on top.
Decorate with the sugared berries and redcurrants, borage flowers and mint leaves (if you have them).