When you want a crumbly topping and a chewy cookie, what’s a person to do? Make my Mint Chocolate Streusel Cookie Bars of course! A chewy, mint chocolate filled cookie, with a crumbly, crunchy oat topping; bliss!

Hello friends. I have a super amazing hybrid dessert for you today!

Because… The other day I wanted a cookie, but I also wanted a crumbly, crunchy top. So, being a recipe developer what was a girl to do?

Create a perfect marriage of the two things I was craving so badly of course to make these Mint Chocolate Streusel Cookie Bars.

Don’t be scared by the green lumps you may see; that’s a Mint Aero bar chopped up and added to my dough. It was the only mint chocolate bar I could find in the store I went to!

But, it’s totally addictive!! I don’t normally like Aero, but the mint one is really refreshing and utterly delicious!

Normally I think of a crumbly topping on top of some tender, juicy fruit, but I was super excited to see how it worked against my base chewy cookie dough.

The result? AH-MAZING.

As you first bite into it you think “ooooh, is this going to be a biscuit?” then you hit that chewy layer and you’re like “OHMYGOSH, NOOOOO, it’s a chocolate filled cookie with a crunchy top!”

Also, because the cookie is baked in an 8×8 inch pan, you don’t have to wait for it to chill like you do with my normal cookies. You know what THAT means….?

Cookies in under and hour. HELLO fat pants.

We’ve had an incredibly busy few days, so there really is nothing I’d like more than a fat pant day, on the sofa, watching TV with one (or three) of these bars in front of me.

Can Wednesday be the new Sunday? Actually scratch that, I just thought of eleventy million things I need to do tomorrow.

Ugh. I do feel like I need a break in the week though. Working for yourself means it’s pretty hard to switch off from work. Especially when work is on the internets… It’s not like it gets to 5pm and then I turn my website off. Sometimes a drama happens at 10pm and I have to try and sort it.

Mind you, that can happen in the *real* world too; something broke at Mr Annie’s Noms work on Friday and the remote “turn it off and on again” wasn’t working, so we had to bundle in the car at 10:30pm and drive 30 miles to basically turn something off and on again.

I don’t really remember it though… the only thing I remember is standing against a wall and almost falling asleep. It’s all fun and games in our household!

Come Saturday morning we both felt drunk on no sleep. Sitting in my pyjamas with a cookie bar felt like absolute heaven. And then we had roast potatoes. Hell yeah!

Anyway, let’s talk about that crumble topping. Oats, butter, sugar and flour. Those 4 basic ingredients make such a magical part of these bars.

There’s just something amazing about lumps of brown sugar that slightly caramelize. And you know how obsessed with oats I am. All day EVERY day!

Now, I said this in a previous crumble recipe, but you can actually use a half fat butter spread if you want (only for the streusel topping); I would never have thought to use it, but a friend asked for a low fat dessert, so I used a half fat spread in my Raspberry Peach Crumble a while back and it was honestly the best crumble I’ve EVER had.

So, for this streusel, go right ahead and use butter or spread, but definitely use real butter in the cookie part! 🙂

My number one tip: Go make these Streusel Cookie Bars right now. They are just the most amazing combination of crunchy and soft. And they’re so easy to make! Ready in under an hour and totally portable, these are my new favourite hybrid dessert!

Mint Chocolate Streusel Cookie Bars

When you want a crumbly topping and a chewy cookie, what's a person to do? Make my Mint Chocolate Streusel Cookie Bars of course! A chewy, mint chocolate filled cookie, with a crumbly, crunchy oat topping; bliss!

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Prep Time 15

Cook Time 25

Total Time 40

Servings 9

Ingredients

For the streusel topping:
1/2 cup (40g) rolled oats
1/4 cup (50g) light brown sugar
3/4 cup (105g) plain flour
1/2 stick (56g) unsalted butter, left out of the fridge for 15 minutes (see note)
1/8 tsp vanilla extract
For the cookie layer:
1 3/4 cups (210g) mint chocolate chips/chunks;** I used 2 Mint Aero sharing blocks and chopped them up
1 cup (140g) plain flour
1/2 cup (70g) bread flour
2 tsp cornflour
1 tsp bicarbonate of soda
Pinch of salt
1 1/4 sticks (140g) unsalted butter, at room temperature
1/2 cup (100g) light brown sugar
1/4 cup (50g) caster sugar
1 large egg
1/4 tsp vanilla extract
1/4 tsp peppermint extract

Instructions

Preheat the oven to 180C/350F and grease and line an 8x8 inch square pan.
Make the streusel first: Place oats, sugar, flour and butter into a medium sized bowl and rub together until it starts to combine. Then add in the vanilla extract and continue rubbing between your fingers until you have a coarse breadcrumb texture. Some larger and smaller lumps are fine! Leave to one side.
Make the cookie layer: Place mint chocolate chips/chunks, flours, bicarb and salt into a medium sized bowl and stir until all the chocolate chunks are coated in flour. Leave to one side.
Place butter and sugars into a large bowl, or the bowl of a stand mixer and beat until light and fluffy, 2-3 minutes on medium-high speed.
Add in the egg, vanilla extract and peppermint extract, scraping down sides as necessary and mix until well incorporated and smooth, 1 minute on med-high speed.
Tip in the flour and chocolate mixture and mix on low until a soft dough forms.
Tip the cookie dough into your prepared pan and press into a level layer with either your hands or the back of a wooden spoon/spatula. (I used my hands, much easier!)
Sprinkle the streusel topping all over the cookie dough (there's plenty to cover it!) and press it into the cookie dough ever so slightly.
Place in the oven for 25-30 minutes until risen around the edges and slightly golden.
It can be a little hard to tell if it's done; it was golden and firm around the edges, the topping was ever so slightly coloured and the centre was still pretty soft and under done. (I made this twice and the first time I over did it as I thought it wasn't cooked in the centre, but underdone will be fine once cooled as it keeps cooking!)
Leave to cool in the pan completely, before transferring to a cutting board to slice into 9-12 bars.
Mint Chocolate Streusel Cookie Bars will keep in an airtight container, at room temperature for 5 days.

Notes

Note: You can use either butter or a half fat butter spread for the streusel topping; I wouldn't normally advise using a half fat spread, but in the past I used it to make a streusel and it was the best streusel EVER!

**Aero is really light, so 1 and 3/4 cups = 210g. For normal chocolate chips 1 cup = 175g, so you would need 1 and 1/4 cups equaling 218g.