Preheat the oven to 350°F. Line a cupcake pan with 12 baking cups.
Place the sugar and pistachios in a food processor and process until the pistachios are finely ground. Set aside.
Melt the butter in a microwave at 60% power for 1½ to 2 minutes. Keep the butter warm; do not allow it to sit and cool off.
In a stand mixer with the paddle attachment, beat the eggs and egg whites on medium-low speed for 2 minutes until lightly foamy.
Increase the mixer speed to medium-high. Pour the warm butter into the eggs slowly, so that the mixture tempers and the eggs do not scramble. Once the butter is added, reduce the speed to medium-low.
With the mixer running, add the milk, vanilla, and salt. Mix for 1 minute until well combined.
Sift together the flour and baking powder and stir into the pistachio mixture. Add to thebatter. Mix on medium until just combined, about 30 seconds. Remove the bowl andpaddle from the mixer and use the paddle to scrape the bottom and sides of the bowl, ensuring that everything is well mixed.
Scoop the batter into the prepared baking cups, filling them two thirdsof the way.
Bake in the middle of the oven for 20 to 25 minutes, rotating the panhalfway through. The cupcakes are done when the centers spring backwhen you touch them.
Remove the cupcakes from the oven. Let cool completely.
French Buttercream (recommended): Prepare the buttercream, add the pressed ricotta and vanilla until fully incorporated.
For American Frosting: Prepare the recipe as directed, only replacing mascarpone with the pressed ricotta, add the vanilla and beat well.
Assembly: Fill a pastry bag fitted with a plain or fluted tip with cannoli buttercream and pipe ontoeach pistachio cupcake.
Mix the chocolate chips, roasted pistachios, and candied citrus, if using, in a bowl and sprinkle on top of the cupcakes.
Half-Assed Corner: Skip the citron if you can’t find it -- which, odds are, you won’t be able to unless you live close to an Italian or Middle Eastern specialty store. It’s not a make-or-break ingredient.
