food & drink

How to create American style M&M cookie bars

As an American child who grew up in the UK, there are a lot of American style foods that I crave on a regular basis.

As an American child who grew up in the UK, there are a lot of American style foods that I crave on a regular basis. This recipe is unbelievably easy and quick, and I can guarantee that you will love these.

They’re the goodness of cookie dough combined with the warm crust of a freshly baked biscuit, and they stay nice and soft for as long as you choose to keep them (although my kitchen staff devoured mine in under ten minutes).

I have to give almost all the credit for this recipe to this lovely cooking blog, but I did make a few edits to help you all out. I should really have called this recipe ‘The Crash Course in Converting American Measurements’ but that may have been less attractive to everyone than COOKIES!

But seriously, converting from US to UK can be complicated and put people off making American style goodies, so I’ve done it for you.

No excuses now – get baking!


325g plain flour (most US recipes are in cups, but even if you have cups it’s usually better to weigh it out in grams. The sizes of cups vary and can be confusing. In reality, a cup of flour is roughly equal to 150g)

1/2 tsp salt

1/2 tsp baking powder (a lot of US recipes will call for baking soda. In the UK we have bicarbonate of soda AND baking powder. Just remember that bicarb = bubbles for batters, while baking powder is to help things rise)

170g butter (bizarrely butter is measured in sticks or tbsp. A stick is roughly 110g, if that helps)

175g soft brown sugar (for some reason, cups of sugar differ to cups of flour. 1 standard cup = 175g)

85g white sugar

1 large egg

1 egg yolk (see here for an amazing way to separate egg yolks)

2 tsp vanilla extract

1 bag of plain chocolate M&M’s (165g)


1. First, preheat your oven to 160 celsius, or gas mark 3.

2. Butter and line a 9×13 inch baking pan with baking paper and set aside for now.


3. Stir together the flour, salt and baking soda in a small bowl, and set aside.



4. Melt the butter. Now, you can do this properly in a pan if you want to, but it truly is much easier to put it in a microwaveable bowl and melt it that way. My Mum would kill me for not telling you to do it on Low for 10 seconds at a time, but nobody has time for that. Microwave it on High for a minute but keep an eye on it! The problems only start when people walk away and/or ignore it when it starts to explode.

5. Mix together the melted butter, brown sugar and white sugar, and then add the egg and egg yolk. The best advice I can give you here is to use a spatula and fold as much air into the mix as possible.

6. Add the vanilla into the mix and then slowly start to incorporate the dry ingredients, bit by bit, until it’s just combined. Try not to over mix everything, or your cookie bars will lose their softness in the middle. Then, throw in the M&M’s (keeping a handful left over for decoration) and loosely work into the mix.

7. Tip the mixture out into your lined tin and press it down until it’s an even layer. The dough should be really soft but not sticky, and easy to press into the corners of the tin. Take the remaining handful of M&M’s and press them into the top of the dough to ensure there is chocolate in every bite.

8. Bake in the oven for around 25-30 minutes. It’s not going to go really brown on top, so don’t panic if it seems a bit undercooked. Slide onto a baking tray and allow to cool completely to get that perfectly chewy centre. Cut into squares and share!

Inspiration: These cookie bars are brilliant because they hold their structure and can be packaged up easily. I packed a few into some decorated boxes and passed them out at work. A great treat or gift for someone and ridiculously easy to do!

What do you think? Have you tried this recipe? Let us know in the comments section below.