Preheat oven to warm. Make 4 peanut butter sandwiches with slightly stale bread. Combine ¾ cup whole milk, 2 eggs, 1 Tbsp. sugar, 1 Tbsp. melted butter (optional), ¼ tsp. salt, and 2 tsp. vanilla extract in a bowl, then pour into a baking pan. Working in batches, soak each sandwich in the mixture until saturated, about a minute. Heat a pat of butter in a skillet over medium-low heat. When butter is melted, remove sandwich with a slotted spatula to drain, then place in skillet. Cook until golden brown, 6 to 7 minutes per side. Keep warm in preheated oven while you make the rest. When ready to serve, top with a spoonful of jam or jelly.
—O reader Sara Grimes, Portland, Oregon