Preheat oven to 180*C.

Mix flour, milo, baking powder, and salt in a large mixing bowl.

In a double boiler, melt butter.

Remove from heat, stir in sugar.

Mix in vanilla extract.

Add egg and mix well.

Add half of the dry ingredients, and mix until just combined.

Then the other half, and mix well.

Pour half the batter into a lined brownie tray.

Bake for 13 - 18 mins or until done.

Set aside to cool.

Pour remaining batter into lined brownie tray and bake until done.

When done, place graham crackers on top while still hot.

Place hershey's chocolate bar.

Add topped with marshmallows.

Put it back in the oven for about 3-5 mins to get marshmallows toasted.

Watch! Make sure it doesn't get burned!

Immediately place the other cooled brownie on top of the toasted marshmallows.

Push it down a little and let it cool completely before cutting.

It is going to be messy cutting it.

Run a knife along the side to release the marshmallows sticking on the baking paper.

Serve with a glass of milk, and enjoy!