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closeup overhead low FODMAP S'mores brownies on black plate

One-Bowl Low FODMAP S’Mores Brownies

I developed our One-Bowl Low FODMAP S’Mores Brownies in response to the huge popularity of the S’more Chocolate Chunk Cookies. In this recipe you can make this jam-packed brownie in one microwave-safe bowl and the result is a moist cocoa-rich brownie topped with mini-marshmallows, milk chocolate and graham crack – all low FODMAP, of course, and this recipe happens to also be gluten-free.

Low FODMAP Serving Size Info: Makes 25 servings; 25 bars; 1 bar per serving

Prep Time: 20 minutes
Cook Time: 35 minutes
Total Time: 55 minutes
Makes: 25 Servings
Calories: 177 kcal
Author: Dédé Wilson


  • ½ cup (113 g; 1 stick) unsalted butter, cut into pieces, at room temperature
  • ½ cup (43 g) sifted natural cocoa
  • ¾ cup (149 g) sugar
  • 1 teaspoon vanilla extract
  • 2 large eggs, at room temperature
  • ½ cup (73 g) low FODMAP gluten-free all-purpose flour, such as Bob’s Red Mill 1 to 1 Gluten Free Baking Flour
  • ¼ teaspoons salt
  • 2 ½- ounces (70 g) milk chocolate, chopped, divided; you can use semisweet chocolate
  • 1 ½- ounces (40 g) low FODMAP graham cracker crumbs, such as from Nairn’s Gluten Free Oat Grahams, roughly crushed, divided
  • 2 cups (85 g) miniature marshmallows


  1. Position rack in middle of oven. Preheat oven to 350°F (180°C). Line the inside of an 8-inch (20 cm) square baking pan with foil, smoothing it out. You can also use parchment paper, which is what I used, as I intended to use a butane torch for the last step (it would burn under a broiler) . Coat the foil or parchment with nonstick spray.
  2. Melt the butter in a large microwave safe bowl. Whisk in the cocoa and sugar until smooth, then whisk in vanilla. Whisk in the eggs one at a time, allowing each to become incorporated before adding the next. Stir in the flour and salt until batter is well-combined and smooth. Scrape into prepared pan. Scatter half the milk chocolate and half the graham cracker chunks over the batter.
  3. Bake for about 25 to 35 minutes or until a toothpick just tests clean. Immediately, while bars are warm, scatter the remaining milk chocolate, graham crackers and marshmallows on top of the brownies in an even layer.
  4. To Toast In The Oven: Adjust the rack about 6-inches (15 cm) from the broiler. Preheat the broiler to high. Place the brownies under the broiler and keep a close eye on them. Your aim is to toast the marshmallows and lightly melt the milk chocolate; take care as the topping can easily burn and the marshmallows can catch fire.

  5. Brown With A Torch: Fire up your propane or butane torch (you have one right? To make crème brulée?) to brown your marshmallows to desired doneness and to lightly melt the milk chocolate. A hand-held torch allows much more precise control than the broiler.

  6. Cool the brownies on a rack for several hours or until completely cool and firmed up. Use the foil or parchment to help lift the bars up and out of the pan. Place on cutting board and peel down the foil. Cut into a 5 by 5 grid into 25 bars. I like using a metal bench scraper, spritzed with nonstick spray, to cut straight down. Wipe and re-coat with nonstick spray between cuts for cleanest results. Use a thin blade slicing knife if you don’t have a bench scraper.
  7. These brownies are best enjoyed the day they are made. You can also store them in an airtight container at room temperature overnight. A friend of mine “refreshed” hers in the microwave briefly to get the marshmallow ooey gooey and said they were divine.


FODMAP Information

Our recipes are based on Monash University and FODMAP Friendly science.

Butter: Both Monash University and FODMAP Friendly have lab tested butter. Monash states that a low FODMAP Green Light portion is 1 tablespoon or 19 g and also states that “butter is high in fat and does not contain carbohydrates (FODMAPs)”. FODMAP Friendly gives it a “Pass” at 1 tablespoon or 19 g. Both recommended serving sizes are presented as part of healthy eating guidelines, not as maximum FODMAP serving size. Fat can affect guy motility and trigger IBS symptoms in some people. Eat to your tolerance.

Chocolate: Monash University has lab tested dark, milk and white chocolate all have low FODMAP amounts: 85% dark at 20 g; dark at 30 g; milk at 20 g; white at 25 g.

Dairy: The low FODMAP diet is not a dairy-free diet. It is however, low in lactose. Many dairy ingredients are low in lactose, such as heavy cream and many cheeses.

Sugar: Monash University and FODMAP Friendly have both lab tested white, granulated sugar. Monash states that a Green Light low FODMAP serving size of white sugar is 1/4 cup (50 g). FODMAP Friendly simply states that they have tested 1 tablespoon and that it is low FODMAP. Regular granulated white sugar is sucrose, which is a disaccharide made up of equal parts glucose and fructose. Sucrose is broken down and absorbed efficiently in the small intestine.

Please always refer to the Monash University & FODMAP Friendly smartphone apps for the most up-to-date lab tested information. As always, your tolerance is what counts; please eat accordingly. The ultimate goal of the low FODMAP diet is to eat as broadly as possible, without triggering symptoms, for the healthiest microbiome.

Nutrition Facts
One-Bowl Low FODMAP S’Mores Brownies
Amount Per Serving
Calories 177 Calories from Fat 54
% Daily Value*
Fat 6g9%
Saturated Fat 1g5%
Sodium 44mg2%
Potassium 10mg0%
Carbohydrates 31g10%
Fiber 1g4%
Sugar 19g21%
Protein 2g4%
Calcium 1mg0%
Iron 1mg6%
* Percent Daily Values are based on a 2000 calorie diet.