Mini Lemon Cupcakes with Perfect Silky Buttercream

For the cupcakes:

Preheat oven to 350 F; fill mini cupcake tins with 36 cupcake wrappers; set aside.

In a medium bowl, whisk flour, baking powder and salt; set aside.

In a separate bowl, combine yogurt, milk, lemon juice, lemon zest, and vanilla; set aside.

In a large bowl using an electric mixer, beat butter and sugar on high speed for several minutes or until light and fluffy. At this point you can’t really overbeat the batter, you want to get as much lightness at this stage as you can. Make sure that you scrape the sides of the bowl a couple of times with a spatula.

Add eggs one at a time, beating at medium speed for one minute after each. Again make sure to scrape the sides of the bowl with the spatula.

Reduce speed to low and slowly add 1/3 of the flour mixture and then 1/2 of wet ingredients; repeat with 1/3 of flour mixture and remaining wet ingredients. Then add remaining flour mixture, mix for just a second and remove the bowl from mixer immediately (there should still be lumps in the batter. Use a spatula to gently fold batter so that you can no longer see any dry ingredients but there are still some small lumps; do not overmix.

Evenly distribute batter into cupcake wrappers; I find this easiest with a medium cookie dough scoop or small ladle.

Bake cupcakes for 10-12 minutes or until a toothpick comes out clean after sticking it into the center of a cupcake; do not overbake. Remove them from the oven and set cupcakes aside to cool while you prepare frosting.

For the Lemon Kissed Swiss Meringue Buttercream:

Use a paper towel soaked with some vinegar to wipe off the clean bowl of an electric mixer, the whisk attachment, whisk, spatula and candy thermometer. You need them good and clean (if any grease is on these items your meringue will not work).

Place egg whites and sugar in mixing bowl over a pot of simmering water; water should not be high enough to touch the mixing bowl. Whisk the mixture slowly but constantly until temperature reaches 160 F, about 5-10 minutes.

Remove the bowl from the stove and attach it to your electric mixer fitted with whisk attachment. Put mixer on low to medium speed and whisk until meringue is shiny and thick and the bowl has cooled down to room temperature. If the bowl does not cool and meringue has formed, you can put an ice bath under the mixing bowl while it is mixing.

Once the meringue is ready, replace whisk attachment with paddle attachment and add cubes of butter one at a time mixing on low speed until the mixture is light and creamy. If mixture gets lumpy, keep mixing for several minutes; if it gets runny, place bowl in the fridge for 10 minutes before continuing to mix. Make sure that you stop the mixer to scrape sides of bowl, then continue to beat on low speed for another minute.

Add lemon zest, vanilla and salt and mix on medium speed until the buttercream is light and creamy.

Frost the cooled cupcakes as desired (I prefer piping for Swiss meringue buttercream).

Notes:
Cupcakes are best that day or refrigerated overnight; may be frozen up to one month and served at room temperature

Cupcakes and frosting adapted from Sweetapolita.