Lime Cupcakes

Ingredients

• 1 cup granulated sugar (200g)
• zest of 1 small lime - about 2 tsp (4g)
• 1/4 cup unsalted butter, room temperature (56g)
• 1/2 cup full-fat sour cream, room temperature (125g)
• 1/2 cup water, room temperature (120g)
• 1 large egg, room temperature (56g)
• 1 tsp vanilla extract or vanilla bean paste (4g)
• green and yellow gel food coloring - optional
• 1 1/4 cup all-purpose flour or gluten free flour blend (150g)
• 1 1/2 tsp baking powder (6g)
• 1/2 tsp fine salt (3g)
• 2 large egg yolks or 1 large egg (40g)
• 1/3 cup granulated sugar (67g)
• 3 Tbsp fresh lime juice or bottled key lime juice (45g)
• 2 tsp key lime zest - zest of 1 small lime (4g)
• 1/4 tsp fine salt (2g)
• 2 Tbsp unsalted butter, cut into small pieces (30g)
• 1 cup unsalted butter, room temperature (226g)
• zest of 1 small lime - about 2 tsp (4g)
• 1 tsp vanilla extract or vanilla bean paste (4g)
• 1/4 tsp fine salt (1g)
• 3 1/2 cups powdered sugar (454g or a 1 lb. box)
• 1 Tbsp fresh lime juice (15g)
• Electric hand mixer or stand mixer
• Muffin tin
• Cupcake liners
• 1 small lime
• Open star piping tip (like a Wilton 1M)
• Large piping bag

Instructions

1. 1

   --- Lime Cupcakes: ---

2. 2

   Preheat oven to 350°F / 175°C, and place 12 cupcake liners in a muffin pan.

3. 3

   Use your fingertips to massage 1 cup of granulated sugar with the zest of 1 lime in a large bowl. This helps release the oil from the lime zest. The mixture should become aromatic.

4. 4

   Add 1/4 cup of room-temperature butter. Mix on a medium-high speed with a hand mixer for a minute to cream together the butter and sugar.

5. 5

   Add 1/2 cup sour cream, 1/2 cup water, 1 large egg, 1 tsp vanilla extract, and a small squirt of yellow and green gel food coloring (optional) into the butter/sugar mixture. Mix on a medium speed until combined. Scrape the sides of the bowl as needed.

6. 6

   Sift 1 1/4 cups all-purpose flour, 1 1/2 tsp baking powder, and 1/2 tsp salt into the wet ingredients.

7. 7

   Mix the batter together until the ingredients are just combined and you can’t see any streaks of flour.

8. 8

   Divide the batter evenly between the cupcake liners, filling them about 2/3 full. Bake for 18-21 minutes or until a toothpick comes out clean.

9. 9

   Let the cupcakes cool for 5 minutes before moving them onto a cooling rack to finish cooling.

10. 10

    --- Lime Curd Cupcake Filling: ---

11. 11

    Make the lime curd next! It needs time to cool to room temperature.

12. 12

    Fill a saucepan with 2 inches of water and heat over medium-low heat.

13. 13

    Combine 2 large egg yolks, 1/3 cup sugar, 3 Tbsp of lime juice, 2 tsp lime zest, and 1/4 tsp of fine salt in a medium-sized, heat-proof bowl. Whisk until combined and smooth.

14. 14

    Once the water begins to simmer, place the bowl on top of the saucepan to make a double boiler. Leave the heat on medium-low heat and make sure the water isn't touching the bottom of the bowl. Continuously whisk the mixture until it thickens. This usually takes me about 3-5 minutes.

15. 15

    Remove the bowl from the pan and turn off the stove. Add 2 Tbsp of butter and whisk until incorporated. The mixture should be thick and smooth at this point.

16. 16

    Scoop the lime curd into a small piping bag and seal the top. Place in the fridge to cool. It should thicken and be chilled in 15-30 minutes.

17. 17

    Leftover lime curd can be stored in the fridge for up to 2 weeks.

18. 18

    --- Lime Buttercream: ---

19. 19

    While the cupcakes bake and cool, make the lime buttercream.

20. 20

    Beat 1 cup of unsalted butter on a medium speed for 30 seconds with a hand mixer until smooth.

21. 21

    Add in the zest of 1 small lime, 1 tsp vanilla extract, and 1/4 tsp salt. Mix on a low speed until the ingredients are incorporated.

22. 22

    Mix in 3 1/2 cups of powdered sugar and 1 Tbsp of fresh lime juice on a low speed. Scrape the sides and bottom of the bowl as needed.

23. 23

    Once fully mixed, if the frosting seems too thick, add additional lime juice (1 tsp at a time). If the frosting is too thin, add more powdered sugar (a quarter of a cup at a time). Or if your frosting looks broken before adding it into the piping bag, add in more room-temperature butter, 1 Tbsp at a time until it comes back together.

24. 24

    Stir the frosting by hand with a rubber spatula once it's made for a minute or two to make the frosting super smooth.

25. 25

    Cut off the tip of the bag and fit it with an open star piping tip (like a Wilton 1M).

26. 26

    Place the buttercream in the piping bag and seal the top with a rubber band.

27. 27

    --- Decorating these Lime Cupcakes: ---

28. 28

    Once the cupcakes have fully cooled, remove the centers with a small sharp knife or a 3/4-inch circle cutter.

29. 29

    Fill the center of each cupcake with lime curd.

30. 30

    Pipe a generous swirl of lime buttercream frosting on top of each cupcake, and garnish with a lime slice and a dusting of lime zest.