Classic Congo Bars (The Ultimate Chocolate Chip Bar Recipe)

Introduction

I first discovered these Congo Bars in algebra class when I was 14 years old—which, admittedly, was more than a few years ago. But here’s what really matters: they’re still the best chocolate chip bars I’ve ever tasted.

That day, when my teacher passed around a sheet of paper, I fully expected a pop quiz or extra homework. Instead, it was a recipe. Our assignment? Use our math skills to double it. Since I had already been baking for a few years, I was thrilled—this was homework I could actually get excited about. One bite later, I was hooked.

These Congo Bars are thick, chewy, buttery, and loaded with chocolate. They strike the perfect balance between a cookie and a brownie, with crisp edges and a soft, gooey center. Decades later, this recipe still holds up—and it never fails to impress.

Why You’ll Love These Congo Bars

• Rich, buttery flavor

• Soft and chewy with gooey centers

• Loaded with two kinds of chocolate

• Easy one-bowl recipe

• Perfect for parties, bake sales, or lunchbox treats

Ingredients

• 1 cup (2 sticks) unsalted butter, room temperature

• 2 cups brown sugar, packed

• 3 large eggs, room temperature

• 1 tablespoon vanilla extract

• 1 teaspoon Kosher salt

• 2 teaspoons baking powder

• 2 ½ cups all-purpose flour

• 1 ½ cups semi-sweet chocolate chunks

• 1 cup milk chocolate chips

How to Make Congo Bars

Step-by-Step Instructions

1. Preheat oven to 350°F (175°C). Line a 9×13-inch baking dish with parchment paper and lightly grease with nonstick spray.

2. In a large mixing bowl, beat the butter and brown sugar with an electric mixer on medium speed for 2 minutes, until light and creamy.

3. Add eggs, vanilla, salt, and baking powder. Mix until fully combined, scraping down the sides of the bowl as needed.

4. Reduce mixer speed to low and add flour, mixing just until incorporated.

5. Stir in the chocolate chunks and chocolate chips by hand.

6. Spread the dough evenly into the prepared pan using a rubber spatula.

7. Bake for about 30 minutes, until the edges are set and lightly golden. The center should look slightly underbaked and gooey.

8. Let cool in the pan for 5 minutes, then remove and cool completely before slicing.

Baking Method Explained

These bars use the creaming method, where butter and sugar are beaten together to create structure and chewiness. Brown sugar adds moisture and depth, while baking powder gives just enough lift without making the bars cakey. Slight underbaking ensures that signature soft, melt-in-your-mouth texture.

Texture & Formation

• Crispy, golden edges

• Dense, chewy middle

• Gooey chocolate pockets throughout

• Firm enough to slice cleanly once cooled

This is what makes Congo Bars different from standard chocolate chip bars—they’re indulgent and rich without being dry.

Storage & Make-Ahead Tips

• Store at room temperature in an airtight container for up to 4 days

• Refrigerate for up to 7 days

• Freeze sliced bars for up to 3 months

• Warm slightly before serving for that fresh-baked feel

Variations & Add-Ins

• Add chopped walnuts or pecans

• Swap milk chocolate for dark chocolate

• Sprinkle flaky sea salt on top before baking

• Add butterscotch or white chocolate chips

For the Lovers of Congo Bars

These bars are perfect for:

• Chocolate chip cookie fans

• Gooey dessert lovers

• Bake sales & potlucks

• Nostalgic, old-school recipes

• Anyone who loves easy, crowd-pleasing treats

Final Thoughts

These Congo Bars aren’t just a dessert—they’re a memory. From a surprise algebra assignment to a lifelong favorite, this recipe has stood the test of time for one simple reason: it’s unbelievably good.

If you love chewy, chocolate-loaded bars with buttery richness, this recipe deserves a permanent spot in your baking rotation