Preheat your oven to 350°F (175°C) to ensure even baking and perfect golden color.
Line two baking sheets with parchment paper to prevent sticking and ease cleanup.
In a large mixing bowl, whisk together the old fashioned oats, unbleached all-purpose flour, rye flour, baking soda, baking powder, and salt until well mixed. Set aside.
In another large mixing bowl, beat together the brown sugar, granulated sugar, and egg until smooth and creamy. Then add the canola oil, creamy peanut butter, honey, and vanilla extract. Mix until well incorporated.
Gradually add the dry ingredients to the wet mixture. Fold together gently using a rubber spatula until just combined, leaving a few lumps.
Using a cookie scoop or tablespoon, drop rounded tablespoons of dough onto the prepared baking sheets, spacing them adequately to allow spreading.
Lightly sprinkle each cookie with fleur de sel salt before baking to enhance flavor with a delightful crunch.
Bake in the preheated oven for 10-12 minutes until lightly golden around the edges. Cool on baking sheets for a few minutes, then transfer to a cooling rack to cool completely.