Prepare your workspace by laying a sheet of parchment paper on a baking pan or clean countertop.
Keep a second sheet of parchment and a rolling pin nearby.
In a spice grinder or food processor, grind the cashews into a fine powder. Be careful to pulse in short bursts to avoid over-grinding, which can turn the cashews into butter.
In a non-stick saucepan, combine the sugar and ¼ cup of water.
Place over medium heat, stirring until the sugar completely dissolves and the syrup comes to a rolling boil.
Reduce the heat to low and immediately add the ground cashews to the sugar syrup.
Stir continuously to combine and prevent lumps.
Continue stirring the mixture for 6 to 8 minutes as it thickens into a smooth, dough-like mass that pulls away from the sides of the pan.
Test for doneness: the mixture is ready when a wooden spoon can stand upright in it for a moment without falling over. Immediately transfer the cashew dough onto the prepared sheet of parchment paper.
Sprinkle the dried rose petals over the top.
Place the second sheet of parchment paper over the dough and, working quickly, use a rolling pin to roll it out evenly to about ¼-inch thickness.
Remove the top sheet of parchment and let the fudge cool completely at room temperature for at least 30 minutes, or until firm.
Once cooled, use a sharp knife or pizza cutter to slice the fudge. Make parallel cuts on a diagonal at 1¾-inch intervals, then cut again on the opposite diagonal to create classic diamond shapes.
Once the cashew mixture is ready, work quickly to transfer and roll it out. It begins to set as it cools, making it harder to shape.
