Line the bottom and sides of an 8-inch square metal pan with parchment paper. Preheat the oven to 300°F. Position a rack in the lower third of the oven.
In a large bowl, toss the cereal, hemp seeds, pecans, sesame (or chia) seeds, pumpkin seeds, flax meal and goji berries to mix.
In a small saucepan, warm the honey, date paste, salt, and vanilla, stirring and mashing until the date paste is dissolved and/or evenly dispersed. Pour the honey mixture over the dry ingredients and fold until all of the ingredients are moistened and sticky.
Scrape the mixture into the lined pan and spread it evenly with a fork. Using the back of the fork tines, press the mixture very firmly all over to compact and adhere the ingredients.
Bake for 25 to 30 minutes, until the top is barely golden (if in doubt, take it out, so that the honey does not get scorched). Cool in the pan.
When cool, lift the bars from the pan. Gently peel off the parchment. Cut into bars or squares with a heavy sharp knife.