Cake Mix Chocolate Blondies are my go-to when I want a pan of bars that taste like a cross between a blondie and a soft cookie. They’re fudgy, chewy, and full of chocolate chips, with that buttery vanilla base that always hits the spot.
I like this version because it stays soft in the middle with set, lightly golden edges, and it slices clean once it cools. The cake mix shortcut keeps it simple, but the texture still feels like a real homemade bar.
For me, these are especially good for cookie trays, casual get-togethers, and weekends when I want dessert without pulling out a mixer. They’re also easy to tweak with nuts or different chips depending on what you have.
Why You’ll Love This Recipe
Fast and Easy: One bowl, basic ingredients, and you’re in the oven quickly. It’s the kind of dessert I make when I want something reliable and low-effort.
Soft and Chewy: These bake up with a dense, chewy center that’s more blondie than cake. The edges set nicely while the middle stays soft.
Big Chocolate Chip Payoff: Chocolate chips in the batter and on top means you get plenty of chocolate in every bar. I like the extra sprinkle on top because it makes them look finished.
Great for Sharing: A 9×13 pan makes a good amount, and the bars travel well. I cut them smaller for parties and bigger for at-home snacking.
Easy to Customize: Walnuts are classic, but you can swap in different chips or leave the nuts out completely. It’s a flexible base recipe.
Ingredients You’ll Need
Blondie Batter
- Yellow cake mix: I use a standard box of yellow cake mix here. It gives you a consistent base and keeps the texture nice and chewy.
- Egg: A whole egg helps the bars set so they slice instead of crumbling. Use a large egg if you can.
- Egg yolk: Don’t skip the extra yolk. It’s a big part of that fudgy, richer blondie texture.
- Unsalted butter: Melted butter makes the batter quick to mix and gives the best flavor. Let it cool slightly so it doesn’t scramble the eggs.
- Vanilla extract: Regular vanilla is great here. It keeps these tasting like a classic blondie instead of just a chocolate chip bar.
- Milk: Just a little milk loosens the batter so it mixes smoothly. Any milk you keep in the fridge works fine.
Mix ins and Pan
- Semi sweet chocolate chips: Semisweet is my go-to because it doesn’t get too sweet. Milk chocolate chips work too if that’s what you have.
- Walnuts (optional): Chopped walnuts add a little crunch and keep things from feeling too one-note. If you’re serving picky eaters, I usually leave them out.
- Nonstick cooking spray: Spray the pan well, especially the corners. These bars are sticky and you’ll be happier later if the pan is prepped well.
- Parchment paper (optional): I like parchment with an overhang so you can lift the whole slab out to slice. It also helps if you want cleaner edges.
Recipe Instructions
- Preheat the oven: Heat the oven to 350°F and set a rack in the middle position.
- Prepare the pan: Line a 9×13-inch pan with parchment paper, leaving an overhang, or grease the pan well with nonstick spray.
- Mix the wet ingredients: In a large bowl, whisk the melted butter, egg, egg yolk, vanilla, and milk until smooth.
- Add the cake mix: Add the yellow cake mix and stir just until you don’t see dry streaks.
- Fold in the mix-ins: Fold in most of the chocolate chips and the walnuts if you’re using them.
- Spread the batter: Press the batter evenly into the prepared pan, then sprinkle the remaining chocolate chips over the top.
- Bake: Bake for 20 to 25 minutes, until the edges are set and lightly golden and the center looks just set. Avoid overbaking.
- Cool: Cool in the pan for at least 30 minutes, then lift out (if using parchment) and cut into bars.
Some of my tips!
This is the part that really makes a difference. If you only read one section, make it this one because this is where I share the little trick that helps the recipe turn out so well.
Recipe Tips & Tricks
Don’t overmix after the cake mix goes in. Stir just until you stop seeing dry streaks. Overmixing can make the bars a little tougher than they need to be.
Press the batter into the corners. The batter is thick, so take a minute to spread it evenly. An even layer helps the center finish at the same time as the edges.
Pull them when the center looks just set. If you wait until the middle looks fully firm, they’ll bake up drier. They continue to set as they cool.
Use a 9-inch square pan for thicker bars. It’s a great option if you like a taller blondie. Start checking around 24 minutes, and expect closer to 24 to 30 minutes total.
Add cornstarch if you want more chew. A tablespoon mixed in with the cake mix makes the texture a little chewier. It’s subtle, but noticeable.
Make some touches!
There are plenty of easy ways to serve this depending on the occasion. Keep it simple, or add a few small touches to make it feel a little more special.
Serving Suggestions
- Milk: A cold glass of milk is simple and classic with these. It’s especially nice if you used semisweet chips.
- Ice cream: Serve a bar with vanilla ice cream on the side. If you warm the bar for a few seconds, keep it short so it doesn’t turn greasy.
- Fruit: Fresh strawberries or raspberries are great with blondies. I like a small handful on the plate instead of doing anything fancy.
- Coffee or espresso: These are really good with coffee, especially in the afternoon. I usually go with something not too sweet, like a latte or black coffee.
Save it for later
This section covers how to store leftovers and what parts of the recipe you can prepare ahead of time.
Storage and Make Ahead
Store the bars covered at room temperature for 2 to 3 days. I keep them in the pan with foil over the top, or move them to an airtight container once they’re sliced.
If you want them to last a little longer, store leftovers covered in the fridge for up to 4 days. They’ll firm up when chilled, so I usually let a bar sit out for a few minutes before eating.
These also freeze well if you want to stash a few away. Freeze individual portions in a freezer-safe container, then thaw at room temperature or in the fridge until soft again.
A few quick answers
This section covers a few extra details that may help before you head to the recipe card.
Recipe FAQs
How do I know when blondies are done baking?
I look for edges that are set and lightly golden, and a center that looks just set (not wet batter, but not fully firm either). If you overbake, the bars lose that fudgy texture.
Can I use oil instead of butter?
Yes. You can swap the melted butter for a neutral oil if you want a softer texture. The flavor is a little less buttery, but the bars still bake up nice and chewy.
Can I use other types of chips?
Definitely. Milk chocolate chips, peanut butter chips, or white chocolate chips all work well here. I keep the amount the same and just swap the type.
Can I bake these in a 9-inch square pan?
Yes, you’ll get thicker bars. Bake about 24 to 30 minutes and start checking early, since every oven is a little different.
Why did my blondies come out dry?
Most of the time it’s from baking a little too long. Pull them when the center looks just set, then let them cool in the pan so they finish setting up without drying out.
You might also like
Before you go, take a look at a few other recipes below the recipe card. They use similar ingredients in a different way and are worth saving too.
MORE DINNER RECIPES TO TRY
Cake Mix Chocolate Blondies
INGREDIENTS
Blondie Batter
- 1 box yellow cake mix 15.25 oz
- 1 large egg
- 1 large egg yolk
- 1/2 cup unsalted butter melted and slightly cooled
- 1 tsp vanilla extract
- 2 tbsp milk.
Mix ins and Pan
- 1 1/2 cups semi sweet chocolate chips
- 1/2 cup chopped walnuts optional
- nonstick cooking spray
- parchment paper optional.
INSTRUCTIONS
Prep
- Heat oven to 350 F and position rack in the middle
- line a 9 by 13 inch pan with parchment leaving overhang or grease well
- whisk melted butter egg egg yolk vanilla and milk until smooth then add cake mix and stir just until no dry streaks remain
- fold in most of the chocolate chips and optional walnuts.
Bake and Cool
- Press batter evenly into the pan and sprinkle remaining chocolate chips over the top
- bake until edges are set and lightly golden and the center looks just set 20 to 25 minutes avoiding overbaking
- cool in pan at least 30 minutes for cleaner slices then lift out and cut into bars.
