Line a baking tray with parchment paper/tin foil and spread the mixed nuts out on the tray, lightly drizzle with the olive oil and toast under the grill for approximately 1 minute or until the nuts have lightly browned, remove and set aside
Preheat the oven to 180℃
Add the oats, oat flour, chia seeds, pumpkin pie spice mix, baking soda, baking powder and stir until combined
Place in the oven for 35 minutes, checking mid-way, if browning too quickly place some tin foil on top and continue to bake
Allow to cool, slice into bars and enjoy (they will last really well in the refrigerator for 3-4 days and can be frozen also)