Peanut Butter Millionaire Shortbread Recipe: Decadent Layered Dessert

This Peanut Butter Millionaire Shortbread is a healthier twist on classic millionaire’s shortbread. A crisp oat shortbread base topped with a peanut butter “caramel” layer and finished with dark chocolate. These bars are oil-free, refined-sugar-free, vegan and gluten-free — simple, delicious, and made with just five main ingredients.

Ingredients & Substitutions

These shortbread bars are straightforward to make and flexible to adapt. Below are the core ingredients and easy substitutions if needed.

• Oat Flour: Used for the shortbread base. Buy it ready-made or pulse rolled oats in a blender for a few seconds. Use certified gluten-free oats if required.
• Maple Syrup: Sweetens the base and caramel. You can swap for agave, honey (if not vegan), or a sugar-free syrup.
• Peanut Butter: Smooth peanut butter is recommended for texture, but any nut or seed butter works for nut-free options.
• Dark Chocolate: Choose dairy-free dark chocolate or vegan chocolate to keep the bars vegan.
• Plant Milk: Optional. A splash added to melted chocolate creates a glossy ganache; skip it if you prefer a thicker chocolate layer.
• Salt: Optional but highly recommended — a pinch of salt brightens the sweetness and enhances flavor.

How To Make Peanut Butter Millionaire Shortbread

These bars are quick and forgiving to make. Follow the steps below for reliably tasty results.

1. Preheat the oven to 180°C / 350°F (160°C fan) and line a loaf tin with a long strip of baking parchment.
2. Make the shortbread base: whisk together the maple syrup and peanut butter until smooth. Stir in the oat flour until the mixture is evenly combined. If needed, use your hands to bring the dough together.
3. Press the dough firmly into the lined loaf tin so the base is compact and level. Bake for 10 minutes. Baking is optional — it deepens the flavour and helps the base bind, but you can press the base into the tin and freeze it instead if you’d rather not bake.
4. Prepare the peanut butter “caramel”: combine the remaining peanut butter with maple syrup and a pinch of salt, mixing until thick and smooth. Spread this layer evenly over the baked or chilled shortbread base. If you like extra texture, sprinkle cacao nibs, chopped nuts or vegan chocolate chips on top, then place the tray in the freezer to set.
5. Melt the dark chocolate using a bain-marie or microwave, stirring frequently to avoid burning. For a glossy ganache, stir in 1–2 tablespoons of plant milk until smooth and pourable.
6. Once the caramel layer has set, remove the shortbread from the tin and slice into bars (the recipe yields eight larger bars; cut smaller for bite-sized pieces).
7. Top each bar with the melted chocolate, letting some chocolate drip down the sides if desired. Finish with a pinch of flaked sea salt and chill in the fridge until the chocolate is set.

You can also spread the chocolate before slicing if preferred, but pouring after slicing gives a more rustic look with chocolate down the edges.

How To Store Peanut Butter Millionaire Shortbread

Store these bars in an airtight container:

• Room temperature: up to 3 days (if they last that long).
• Refrigerator: up to 1 week.
• Freezer: up to 3 months — ideal for keeping a stash on hand.

Baking in grams & tips

I test recipes to be consistent and simple. For best results, measure ingredients by weight when possible — a kitchen scale improves accuracy and makes baking more reliable. If you don’t have a scale, use trusted conversion charts to help translate cup measurements to grams.

Dust off your apron and enjoy baking these healthier millionaire shortbread bars — they’re indulgent enough to impress but made with wholesome ingredients.