Preheat an oven to 180 degrees C. Line a 33x22cm cake tin with lightly-greased baking paper; 2cm or so of baking paper should stick up on 2 sides to form lifting handles.
Mix the quick oats, rolled oats, pumpkin seeds, almonds, mixed nuts, cranberries and sweetened condensed milk together in a bowl; spread into the prepared tin, evenly pressing into the corners and out to the sides.
Bake in the preheated oven until the edges are golden brown, 20-25 minutes, using slightly less time for chewier bars and slightly more time for crunchier bars.
Allow the the bars cool for 5 minutes in the pan before using the baking paper to lift them from the tin. Use a sharp knife to cut into bars. Let the bars cool completely and store in an airtight container.
It's easy to press the oat mixture into the pan using wet hands or a wet spatula. The water keeps the oat mixture from sticking to you or your utensil.