MUFFINS
2 cups all-purpose flour
2 teaspoons baking powder
1/4 teaspoon kosher salt
1 stick unsalted butter, melted and cooled
1/2 cup whole milk
3/4 cup granulated sugar
1/4 cup light brown sugar
1 teaspoon finely grated lemon zest
2 large eggs
1 1/2 cups blueberries
BANANA BUTTER
6 tablespoons unsalted butter, at room temperature
1 very ripe banana, sliced
1/2 teaspoon fresh lemon juice
Pinch of kosher salt