punition sandwiches

INGREDIENTS

• 1 1/4 sticks (5 oz; 140 g) unsalted butter, at room temperature [I used salted, just my preference, and fodder for a whole other post.]
• Slightly rounded 1/2 cup (125 g) sugar
• 1 large egg, at room temperature
• 2 cups (280 g) all-purpose flour