a 48-hole mini cupcake pan or two 24-hole mini cupcake pans; 48 mini paper cupcake liners
For the batter: Preheat the oven to 350 degrees F; line a mini cupcake pan with paper liners (use one 48-hole pan or two 24-hole pans).
Sift together the flour, baking powder, baking soda and salt in a medium bowl and set aside.
In the bowl of an electric stand mixer fitted with a paddle attachment, cream together the granulated sugar and butter until light and fluffy, 1 to 2 minutes. Add in the eggs one at a time, letting them incorporate fully between additions. With the mixer on low, add in half of the flour mixture, followed by the milk, and then the remaining flour mixture; let each incorporate fully before the next addition. Then mix in the lemon and lime juice and lemon extract.
Using a scoop, fill each mini cupcake cup three-quarters full with batter. Bake until golden and cooked through, 12 to 14 minutes. Remove the cupcakes from the pan and allow them to cool completely.
For the glaze: While the cupcakes are cooling, whisk together the powdered sugar, milk and lemon and lime zest in a bowl until smooth.
Once the cupcakes have cooled, dip the top of each cupcake in the glaze, allowing the excess to drip back into the bowl. Chill the cupcakes in the fridge for at least 30 minutes. Serve cold and enjoy.