Cover the kitchen benchtop with two layers of good quality non-stick baking paper, it should be 30cm (12in) in length. If the edges curls in our up, use mugs on each corner to hold it down. Lightly spray a heatproof spatula and the baking paper with oil.
In a small to medium heavy-based saucepan add in the sugar and the water, do not stir. Place the saucepan on low heat until the sugar has dissolved (it'll look translucent and small bubbles will appear at the base) then increase the heat to medium. Without disturbing the mixture, let the syrup bubble away but watch it carefully as soon as it reaches a nice golden amber colour and it smells like toffee take it quickly off the stove. If using a thermometer it'll reach this stage between 165°C - 170°C (330°F - 340°F)
Working quickly, add the butter to the saucepan and stir quickly with the spatula until the butter has completely melted and the sugar syrup is no longer foamy. Add in the nuts or sesame seeds, give it a quick stir and pour the mixture onto the baking paper. Don't scrape the leftover sugar mixture out of the saucepan as this may cause your brittle to crystallise. Leave the brittle to cool and set completely on the baking baker, then break it into shards.
Notes
(NOTE 1)Caster sugaris also known as ‘superfine sugar’ or ‘baker’s sugar’. It has a finer consistency than white or granulated sugar but it isn't the same as powdered sugar (also known as confectionary or icing sugar)(NOTE 2) Butter - use good quality butter or butter that you enjoy the taste of.(NOTE 3) Nuts or sesame seeds - You can use your favourite nuts or sesame seeds, either way, I highly recommend taking the time to roast them. Roasting will intensify the nutty flavour and make it aromatic. If you are using big nuts such as pecans or walnuts you'll need to chop them up.Leftovers - Place brittle in an airtight container and store it at room temperature, it'll keep up to 2 weeks.A Third-Party Application calculated the calories and nutritional information, so this is an approximate guide only.Cooking measurements are in Australian standard spoon and cup measurements.