Preheat oven to 170°C. Cream the butter and sugars for at least 5 minutes until the mixture becomes light and fluffy.

Add the egg and vanilla extract and beat well.

Add choc chips, flour, baking soda and baking powder. Beat on low speed until just combined (don't overwork the mixture or it can become tough).

Dollop tablespoon sized balls of cookie dough onto lined baking trays. I usually put 5 cookies on each of my 4 trays as these babies spread.

Bake until cookies are golden around the edges, around 12-14 minutes.

Melt the chocolate in a small bowl in the microwave on medium high in 30 second bursts. Once completely melted, set aside.

Place half of the cookies on a baking tray, flat-side up. Place several marshmallows on top of each cookie.

Use either a kitchen blowtorch to melt the marshmallows, or place the baking tray on the highest rack of your grill and toast until blistered and brown (watch them like a hawk though, they burn easily!)

Drizzle the chocolate over the toasted marshmallows, then place the remaining cookies on top and squish into sandwiches. This recipe makes 20 cookies, so 10 cookie sandwiches.

Make a mess and enjoy!