Grease a 23cm x 33cm slice pan; line base and sides with baking paper, extending paper 2cm over long sides.
Combine sesame seeds and pepitas in a large frying pan over low heat; cook, stirring continuously, for 5 minutes or until sesame seeds are light brown. Stir in cranberries. Remove pan from heat.
Heat honey in a medium saucepan over medium heat until just starting to boil; add sesame seed mixture and cook, stirring, for 5 minutes until golden brown.
Carefully pour seed mixture into prepared pan; smooth the top using the back of a large spoon. Place a sheet of baking paper over the top, then a baking tray large enough to fit inside the slice pan; gently press to flatten and compress (this will ensure a smooth and even slice). Stand at room temperature for 30 minutes or until firm.
Transfer slice to a chopping board and cut into 16 even pieces.
Snaps can be made up to 2 weeks in advance; store in an airtight container.