In a medium bowl, stir together oats, chia seeds, flax seeds, peanut butter, honey, cinnamon, coconut, and raisins until forming a homogeneous mixture.
Line an 8 x 8-inch baking dish with parchment paper and press very, very well the bar mixture into the pan using a spatula, until forming a flat, uniform layer.
Lift the parchment paper by holding the overlapping sides and placing it onto a large baking sheet. With a sharp Chef's knife, slice it evenly into 12 bars.