These oven baked 5-ingredient molasses peanut butter bars are the kind of shortcut dessert that feels tailor-made for a packed weeknight. Mary Jane candies bring that old-school peanut butter and molasses flavor, and baking them into simple pantry staples turns them into chewy, rich bars with almost no fuss. This is the sort of treat I’d make when I want something nostalgic and homemade-looking without spending my whole evening measuring, chilling, and decorating.
Serve these bars with a cold glass of milk, hot coffee, or a mug of black tea to balance their sweet, deep molasses flavor. For a casual dessert plate, add fresh apple slices or a few berries on the side, and if you’re bringing them to a potluck, they pair especially well with vanilla ice cream for an easy warm-and-cold dessert combo.
Oven Baked 5-Ingredient Molasses Peanut Butter Bars
Servings: 16 bars
Ingredients
24 whole unwrapped Mary Jane peanut butter molasses candies
1 cup creamy peanut butter
1 cup light brown sugar, packed
2 large eggs
1 teaspoon vanilla extract
Directions
1. Preheat your oven to 350°F and lightly grease an 8x8-inch oven-safe metal sheet pan or small metal baking pan if needed. Spread the whole unwrapped Mary Jane candies evenly across the bottom of the pan.
2. In a medium mixing bowl, stir together the peanut butter, brown sugar, eggs, and vanilla extract until smooth and fully combined. The batter will be thick.
3. Spoon the batter over the candies and gently spread it into an even layer so the candies are mostly covered.
4. Bake for 22 to 26 minutes, until the top looks set and lightly browned around the edges. The center may still look a little soft, which is perfect for chewy bars.
5. Let the bars cool completely in the pan before slicing into 16 squares. As they cool, the candies melt into the bars and create pockets of rich molasses-peanut butter flavor.
Variations & Tips
For easier slicing: Line the pan with parchment before adding the candies and batter if you want to lift the whole slab out in one piece. I like doing this when I’m packing bars for a work lunch or party tray.
For a saltier finish: Sprinkle a light pinch of flaky salt over the batter before baking. It gives the bars a sweet-salty balance that makes the peanut butter and molasses flavors pop a little more.
For a softer candy layer: If your Mary Jane candies are especially firm, let them sit at room temperature for a bit before baking so they melt more evenly into the bars.
For make-ahead storage: Store the cooled bars in an airtight container at room temperature for up to 4 days. If your kitchen runs warm, a quick chill in the fridge will make them firmer and even easier to cut cleanly.