Grease a 23cm tin. Stir together the coconut and condensed milk in a large, microwave-safe bowl. Cook on High in the microwave for 7 minutes, stirring every 30 seconds. When the coconut mixture is hot and bubbling, stir in the almonds and cardamom. Pour into the prepared tin, and smooth the top with a spatula.
Cool for 1 hour in the refrigerator, then cut into 2.5cm squares with a greased knife.