Preheat oven to 350 degrees.

Line an 8 inch square pan with parchment paper or grease well with butter.

Combine the butter, brown sugar, and white sugar in a large bowl and beat to combine. Add the egg, egg yolk vanilla, syrup, and baking soda.

Stir in the peanut butter. Add the oats and stir until well combined. Mix in the chocolate chips.

Press the dough into the bottom of the prepared pan. Top with the M&M's and lightly press them into the dough. Bake for 16 to 17 minutes or until the bars are lightly browned and just past looking wet on top. They will not be firm, but they will set up as they cool. Let it cool completely before slicing. Store in an air tight container.