Preheat oven to 350F/180C. In a large bowl, toss together oats, unsalted nuts, and whole seeds for toasting. Spread them in an even layer on a pan lined with parchment paper or a silicone baking mat. Bake for 7-9 minutes, until golden brown, stirring twice while baking to prevent burning. Scrape mixture back into bowl.

Add nutritional powders: flax meal, arrowroot, protein powder, maca powder, and nutritional yeast to the bowl of toasted oats, nuts, and seeds mixture.

Reduce oven temperature to 300F/150C. Line an 8x8 or 9×9-inch, or similarly sized small rectangular pan with parchment paper, leaving enough overhang on the sides for lifting the bars after baking.

In a medium heatproof bowl, place butter (or oil), nut butter (or tahini), honey/maple, and sugar, and heat it in the microwave or in a saucepan over medium heat until butter has melted and mixture is warm. Stir in salt and spices. Let it sit and cool briefly (about 5 minutes). Stir in egg whites to the dry oat mixture.

Pour butter mixture into oat mixture and toss until evenly moistened. Add dried fruits and chocolate chips, and mix until incorporated (make sure mixture isn’t too warm before adding the chocolate chips or they will melt).

Pour mixture into prepared pan, pressing down evenly and firmly for 1 minute (this will help create less crumbly bars). Bake for 20-30 minutes, depending on the thickness of your bars, until golden brown. The mixture shouldn’t be hard, but rather soft and elastic when lightly pressed. Allow to cool to room temperature, then cover with plastic wrap and refrigerate for at least 2 hours before cutting into bars. Cold bars are best for cutting. Warm bars may crumble while cutting.

Store bars in an airtight container at room temperature for up to a week. For longer storage, wrap the bars in plastic cling wrap and freeze in airtight containers. Grab and go as needed. The bars will thaw very quickly as they don't harden in the freezer too much.