In a large pan over medium heat, roast macadamia nuts until fragrant, stirring occasionally. Remove from heat, cool, and chop into small pieces.
In a separate bowl, whisk rice flour, sugar, and salt. Add vegetable oil and mix until crumbly. Gradually add water, stirring until it forms dough.
Grease or line a square/rectangular baking dish.Press dough evenly into the dish. Bake at 350°F for 20-25 mins, until edges are golden brown.
Let cool briefly, then cut into bite-sized pieces.