Quick Recipe Version (TL;DR)
Amish Chocolate Peanut Butter Oatmeal Bars bring together a buttery oat crust, a thick chocolate-peanut butter filling, and a golden crumble topping. This farmhouse-inspired tray bake is simple to make and even easier to share.
Quick Ingredients
- 1 cup (227 g) unsalted butter, melted and cooled slightly
- 1 cup (200 g) packed light brown sugar
- 2 teaspoons vanilla extract, divided
- 1 1/2 cups (180 g) all-purpose flour
- 2 1/2 cups (225 g) old-fashioned rolled oats
- 1/2 teaspoon baking soda
- 1/2 teaspoon fine salt
- 1 can (14 ounces; 397 g) sweetened condensed milk
- 3/4 cup (192 g) creamy peanut butter
- 1 cup (170 g) semisweet chocolate chips
- 1/3 cup (45 g) chopped salted dry-roasted peanuts
Do This
- 1. Heat the oven to 350°F (175°C). Line a 9 × 13-inch metal baking pan with parchment paper.
- 2. Mix the melted butter, brown sugar, and 1 teaspoon vanilla. Stir in the flour, oats, baking soda, and salt until crumbly.
- 3. Reserve one-third of the oat mixture. Press the rest firmly into the pan and bake for 10 minutes.
- 4. Meanwhile, warm the condensed milk, peanut butter, and chocolate chips over low heat for about 5 minutes, stirring until smooth. Remove from the heat; stir in the remaining 1 teaspoon vanilla and the chopped peanuts.
- 5. Spread the filling over the warm crust, then scatter the reserved oat mixture over the top.
- 6. Bake for 25 minutes, until the edges and crumble are golden and the center remains slightly soft. Cool in the pan for 2 hours before cutting into 24 bars.
Why You’ll Love This Recipe
- One mixture does double duty: The buttery oat mixture makes both the sturdy bottom crust and the crumbly topping.
- A generous, fudgy middle: Chocolate, peanut butter, and condensed milk melt into a rich filling with little effort.
- Comforting texture in every bite: Hearty oats and chopped roasted peanuts balance the soft chocolate layer.
- Made for sharing: One pan gives you 24 neatly portioned bars for potlucks, bake sales, or afternoon treats.
Grocery List
- Produce: None needed.
- Dairy: Unsalted butter; one 14-ounce can sweetened condensed milk.
- Pantry: Light brown sugar, vanilla extract, all-purpose flour, old-fashioned rolled oats, baking soda, fine salt, creamy peanut butter, semisweet chocolate chips, and salted dry-roasted peanuts.
Full Ingredients
For the Oatmeal Crust and Crumble Topping
- 1 cup (227 g) unsalted butter, melted and cooled for 5 minutes
- 1 cup (200 g) packed light brown sugar
- 1 teaspoon vanilla extract
- 1 1/2 cups (180 g) all-purpose flour, spooned into the measuring cup and leveled
- 2 1/2 cups (225 g) old-fashioned rolled oats
- 1/2 teaspoon baking soda
- 1/2 teaspoon fine salt
For the Chocolate Peanut Butter Filling
- 1 can (14 ounces; 397 g) sweetened condensed milk, not evaporated milk
- 3/4 cup (192 g) creamy peanut butter, preferably a conventional no-stir variety
- 1 cup (170 g) semisweet chocolate chips
- 1 teaspoon vanilla extract
- 1/3 cup (45 g) salted dry-roasted peanuts, roughly chopped
Step-by-Step Instructions
Step 1: Prepare the oven and pan
Place a rack in the center of the oven and preheat to 350°F (175°C). Line a 9 × 13-inch metal baking pan with parchment paper, leaving an overhang along the two long sides so you can lift out the cooled bars. Lightly butter any exposed parts of the pan.
Melt the butter and let it cool for 5 minutes. It should still be liquid but no longer piping hot.
Step 2: Mix the oatmeal crust and topping
In a large bowl, stir together the melted butter, brown sugar, and 1 teaspoon vanilla until evenly combined. Add the flour, rolled oats, baking soda, and salt. Stir with a sturdy spoon or spatula until no dry flour remains and the mixture forms moist, loose clumps.
Set aside one-third of the mixture, approximately 280 g, for the topping. The remaining two-thirds will form the bottom crust.
Step 3: Press and partially bake the crust
Transfer the larger portion of the oat mixture to the prepared pan. Press it firmly and evenly across the bottom, working it into the corners. The flat bottom of a measuring cup makes this especially easy.
Bake for 10 minutes. The crust should look set and just barely golden around the edges; it will finish baking after the filling is added. Leave the oven on.
Step 4: Make the chocolate peanut butter filling
While the crust bakes, combine the sweetened condensed milk, peanut butter, and chocolate chips in a medium, heavy-bottomed saucepan. Warm over low heat for about 5 minutes, stirring constantly and scraping the bottom, until the chocolate melts and the filling is smooth and glossy. Do not let it boil.
Remove the saucepan from the heat. Stir in the remaining 1 teaspoon vanilla and the chopped roasted peanuts. The filling will be thick but spreadable.
Step 5: Add the filling and crumble topping
Spoon the warm filling over the warm crust. Gently spread it into an even layer with an offset spatula or the back of a spoon, taking care not to drag up the crust.
Scatter the reserved oat mixture over the filling in small, irregular clumps. Leave a few gaps so the chocolate layer peeks through. Do not press the topping down.
Step 6: Bake until golden at the edges
Return the pan to the oven and bake for 25 minutes. The edges should be golden brown, the oat topping should look lightly toasted, and the filling should be set around the perimeter but still slightly soft in the center.
A toothpick is not a useful doneness test here because the chocolate layer stays fudgy. Avoid baking until the center feels firm; it will continue to set as the bars cool.
Step 7: Cool completely and slice
Set the pan on a wire rack and cool for 2 hours, or until the pan and filling have reached room temperature. Cutting while warm can cause the filling to squeeze out and the crust to crumble.
Lift the slab out using the parchment overhang and place it on a cutting board. Cut into 24 bars, arranged in 4 rows by 6 columns. Wipe the knife between cuts for tidy layers. If your kitchen is warm and the filling remains too soft to cut cleanly, refrigerate the cooled slab for an additional 20 minutes before slicing.
Pro Tips
- Use rolled oats for the best texture: Old-fashioned oats give the crust a hearty bite. Steel-cut oats will not soften properly in this recipe.
- Choose no-stir peanut butter: Its consistent texture helps the filling set predictably. Very oily natural peanut butter can make the middle greasy or softer than intended.
- Pack the base, not the topping: A firmly pressed crust supports the filling, while loosely scattered topping stays pleasantly crumbly.
- Keep the saucepan heat low: Condensed milk and chocolate can scorch quickly. Stir continuously and remove the pan as soon as the mixture is smooth.
- Let cooling do its work: These bars are meant to have a tender, fudgy center, but they need to cool fully before they become easy to portion.
Variations
- Darker chocolate: Replace the semisweet chocolate chips with 170 g of chopped 60–70% dark chocolate for a less sweet chocolate layer.
- Extra peanut crunch: Use 3/4 cup (192 g) conventional crunchy peanut butter instead of creamy, keeping the chopped peanuts as written.
- Warm cinnamon oats: Add 1/2 teaspoon ground cinnamon to the flour and oats for a gently spiced crust and topping.
Storage & Make-Ahead
Room temperature: Store fully cooled bars in an airtight container for up to 2 days in a cool kitchen, placing parchment between layers. Refrigerator: Refrigerate for up to 1 week; let individual bars stand at room temperature for 20–30 minutes before serving for a softer bite.
Freezer: Wrap individual bars tightly, place in a freezer-safe container, and freeze for up to 2 months. Thaw overnight in the refrigerator. Make-ahead: Bake the bars 1 day before serving and leave the cooled slab covered in the pan overnight before slicing. The layers settle nicely and cut especially well the next day.
Nutrition (per serving)
Calories: 311 kcal | Carbs: 36g | Protein: 6g | Fat: 17g | Saturated Fat: 8g | Fiber: 2g | Sugar: 22g | Sodium: 145mg | Cholesterol: 26mg
Nutrition is an estimate for 1 of 24 bars made with the listed ingredients. Values vary by brand and portion size.
