KEY LIME CUPCAKES

Ingredients

• 1 + 3/4 cups all-purpose flour
• 1 tsp baking powder
• 1/2 tsp baking soda
• 1/2 tsp salt
• 1 cup full-fat sour cream
• 1/2 cup (1 stick) unsalted butter, at room temperature
• 1/2 cup granulated sugar
• 1/4 cup light brown sugar
• 1/2 tsp key lime extract (I bought from Amazon here)
• 2 tsp finely grated lime zest
• 1 large egg plus one egg yolk, at room temperature
• 1 and 1/2 TBSP key lime juice
• 1/2 cup (1 stick) unsalted butter, very soft
• (1) 8 oz block full-fat cream cheese, very soft
• 4 + 1/2 cups confectioners’ sugar
• 1/4 tsp salt
• 1 + 1/2 TBSP key lime juice
• 1/4 tsp key lime extract
• 1 tsp finely grated key lime zest
• 1 tsp freshly grated key lime zest