Oatmeal Cookie Bars
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These oatmeal cookie bars are a heartier, chewier version of my chocolate chip cookie bars! Buttery, thick, chewy, and chock full of oats and (optional) chocolate pieces, these are easy to make with no mixer required!
Be sure to check out my step-by-step video just below the recipe!

Cookie bars are the ultimate sweet treat for when you really want cookies but are just too lazy to spend an hour scooping cookie dough.
Alright, so they’re really good anytime, but I’ve been there before too many times to count. Some of my favorite recipes were born of sheer laziness and cookie dough scooping fatigue (I’m looking at you, sugar cookie bars).
And while the lazy factor is a big plus for me, the best part is that we sacrifice nothing in terms of taste. These oatmeal cookie bars are like one of my big soft oatmeal cookies, only even thicker and chewier and loaded with a variety of (optional) chocolate chips. Oh and let’s not forget the best part: no chilling and no scooping required!

While you can make these cookie bars “plain” with no add-ins, I love adding chocolate chips or even chopped nuts to mine. For today’s oatmeal cookie bars I used a blend of milk and semisweet chocolate and butterscotch chips.
Occasionally I’ll toss in chopped walnuts as well. My last batch was a mix of walnuts, dark chocolate and caramel chips (here’s where I’d insert the drooling emoji if I could find it on my keyboard).
You can add your favorite add-ins, but I recommend only using about a cup and a half.

If you’re feeling a little lazy yourself this morning (or evening, or whenever you’re reading this) but also hear your sweet tooth calling, this is the dessert for you.
Let me know what you think of it! My sister-in-law loved these and if you like them half as much as she did they’ll be well worth your time.
Enjoy!
Looking for more lazy-day bar cookie recipes?

Oatmeal Cookie Bars

Ingredients
- 1 cup (226 g) butter, melted
- 1 cup (200 g) light brown sugar, tightly packed
- ½ cup (100 g) sugar
- 2 large eggs + 1 large egg yolk
- 1 ½ teaspoons vanilla extract
- 1 ¼ cup (157 g) all-purpose flour
- 2 teaspoons cornstarch, cornflour in UK
- ½ teaspoon baking powder
- ¾ teaspoon salt
- ¼-½ teaspoon ground cinnamon, optional
- 3 cups (285 g) old fashioned rolled oats
- 1 ½ cups (255 g) chocolate chips, optional, I did a mix of semisweet chocolate chips, milk chocolate chips, and butterscotch chips
Instructions
- Preheat oven to 350F (175C) and line a 9x9 metal baking pan with parchment paper or grease and flour the sides and bottom of the pan.*
- Combine butter and sugars in a large bowl and stir until well-combined.1 cup (226 g) butter, 1 cup (200 g) light brown sugar, ½ cup (100 g) sugar
- Add eggs and vanilla extract and stir well.2 large eggs + 1 large egg yolk, 1 ½ teaspoons vanilla extract
- In a separate bowl, whisk together flour, cornstarch, baking powder, salt, and cinnamon (if using).1 ¼ cup (157 g) all-purpose flour , 2 teaspoons cornstarch, ½ teaspoon baking powder, ¾ teaspoon salt, ¼-½ teaspoon ground cinnamon
- Gradually add dry ingredients to wet until completely combined.
- Add oats and chocolate chips and stir until well combined.3 cups (285 g) old fashioned rolled oats, 1 ½ cups (255 g) chocolate chips
- Spread cookie dough evenly into prepared baking pan and bake on 350F (175C) for 35-40 minutes or until a toothpick inserted in the center comes out clean or with a few moist crumbs.
Notes
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.
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I made these for a hangout with some friends and everyone loved them! I did make a couple changes: one person in the group has a dairy allergy so I swapped for dairy-free chocolate chips and avocado oil instead of butter. Thank you for this recipe!
For those curious about the changes I made: the oil swap did work and didn’t leave a weird taste. I just made a couple mistakes that made the bars turn out not quite as good- a full cup of oil looked like a lot so I used probably more like 3/4-7/8 of a cup. I should’ve kept the full cup because the bars turned out a little drier than I would’ve hoped so don’t make the same mistake! I also used a 9.5×13.5 glass pan (all I had) and it worked just fine. I did 40min but I should’ve kept it to the 35min.
your recipes are very good and precise