Preheat the oven to 200C/180C Fan/Gas 6. Line an 8″ Square baking tin.
In a medium saucepan combine the butter, brown sugar and golden syrup and heat on low until the butter has melted. Turn off the heat and stir in the oats and pretzels.
Quickly stir through the chocolate chips (they may melt a little so work quickly). Pour the mix into the tin.
Press the mixture right to the edges, creating an even layer. Add extra pretzels onto the top of the mixture if you like!
Bake for 20-25 minutes, until golden brown (it will continue to cook a little once out of the oven). Cool on a wire rack before slicing and serving.