Preheat oven to 350℉. Line a cupcake tin with liners and set aside.

To make the cake, pour the shelled pistachios in the bowl of a food processor and pulse until finely ground and resembles the texture of almond flour. Do not over grind because it'll end up like a paste. In a large bowl, combine the flour, baking powder, cardamom, salt and finely ground pistachios. Whisk until evenly combined. Set aside.

In a large mixing bowl, beat together the butter and granulated sugar until light in color and fluffy, about 3 minutes. Add in the eggs, one at a time, mixing well after each addition. Stir in the vanilla and lemon zest. Add the dry ingredients, alternating with the buttermilk. Starting and ending with dry. So a third of the dry and stir. Then half of the milk and stir. A third of the dry and stir. The rest of the milk and stir. And then the last third of dry and stir. After each addition, only mix until just incorporated.

Using a large ice cream scoop, fill the prepared cupcake tin with the batter, filling just a little over half in each. Bake for about 18 to 20 minutes or until golden brown and a toothpick inserted in the middle comes out clean. Remove from oven and allow to cool down completely before frosting.

To make the buttercream, beat the egg whites with an electric mixer, fitted with the whisk attachment, until forthy. Add the cream of tarter and mix until soft peaks form. Slowly add in the granulated sugar, as the mixer is running. Raise the speed to high and beat until glossy and stiff. Switch to the flat beater attachment and mix on low. Add the butter a few tablespoons at a time, mixing well after each addition. Stir in the powdered sugar, salt and vanilla extract. Raise the speed to high and beat until fluffy, about 3 minutes. Stir in the strawberry preserves until streaks form.

Frost the cooled cupcakes with the buttercream and top with a sliced strawberry halve. Serve immediately or store in fridge until ready to eat. Enjoy!