Ingredients

• 14 tablespoons (196 grams) unsalted butter, at room temperature, plus more for the pan
  
• 1 ¹/₄ cups (250 grams) granulated sugar
  
• ¹/₂ teaspoon baking powder
  
• ¹/₂ teaspoon kosher salt
  
• 3 large eggs, at room temperature
  
• 1 large egg yolk, at room temperature
  
• ¹/₂ cup (120 grams) sour cream, at room temperature
  
• 1 teaspoon vanilla extract
  
• 1 ¹/₂ cups (187 grams) all-purpose flour