Line a 9x9 dish with parchment, lightly grease the paper and set aside.
In a large sauce pan over medium low heat, melt together the maple syrup, almond butter, coconut sugar and sea salt, stirring until smooth.
Remove from heat and stir in the cocoa powder, mixing until lump-free. Stir in the vanilla.
Stir in the oats, 1/2 cup at a time. It gets very hard to mix but that means they will hold together well. Stir in the slivered almonds, then fold in the rice crisp cereal.
Transfer the mixture to the lined 9x9 and press it in really well.
Sprinkle the top with chia seeds and, using the back of a spoon, press the seeds into the top of the mixture.
Set in the freezer for an hour, then slice into bars.
Store, covered, in the fridge or freezer for up to a week.