“The cakes were moist and tasty, and the glaze was a perfect sour balance to the sweet cake.” — Grace, recipe tester, age 13
For the Pans
Cakes
Glaze
For the pans: Adjust oven rack to lower-middle position and heat oven to 325 degrees. In small bowl, use spoon to stir together 2 tablespoons sugar and 2 tablespoons melted butter. Use pastry brush to thoroughly paint inside of each cup of 12-cup muffin tin with butter-sugar mixture.
For the cakes: In large bowl, whisk together flour, salt, baking powder, and baking soda.
In bowl of stand mixer (or large bowl if using handheld mixer), combine 6 tablespoons softened butter and remaining ⅔ cup sugar. Lock bowl into place and attach paddle to stand mixer, if using.
Start mixer on medium-high speed and beat until mixture is pale and fluffy, 3 to 4 minutes. Stop mixer.
Use rubber spatula to scrape down sides of bowl. Add eggs and vanilla. Start mixer on medium speed and beat until combined, about 30 seconds. Stop mixer.
Carefully add half of flour mixture. Start mixer on low speed and mix until combined, about 30 seconds. With mixer running, pour in buttermilk and mix until combined, about 30 seconds. Stop mixer.
Add remaining flour mixture. Start mixer on low speed and mix until well combined, about 30 seconds. Stop mixer. Remove bowl from stand mixer, if using.
Use rubber spatula to scrape down sides of bowl and stir in any remaining dry flour. Use large spoon to divide batter evenly among muffin tin cups (use rubber spatula to scrape batter from spoon if needed) and smooth tops.
Place muffin tin in oven. Bake until cakes are light golden brown and toothpick inserted in center of 1 cake comes out clean, about 15 minutes.
Use oven mitts to remove muffin tin from oven (ask an adult for help). Place muffin tin on cooling rack and let cool for 10 minutes.
Use oven mitts to invert muffin tin over cooling rack (ask an adult for help—muffin tin will be hot) and gently tap muffin tin cups to help cakes release. Let cakes cool completely on rack, bottom side up, about 30 minutes.
For the glaze: In second small bowl, whisk together confectioners’ sugar, zest, and 2 tablespoons juice. Whisk in additional juice as needed until glaze is thick but pourable.