Melt butter in a medium saucepan over medium heat. Stir in the sugar, milk, and Simply Sesame until well-blended and smooth. Mix in the oats a 1/2 cup at a time, until the mixture is stiff (you can add more oats if needed).
Line a square baking pan with parchment paper leaving extra paper over the sides of the pan. Spread the oat mixture into the pan, pressing it in evenly. Top with mini chocolate chips, if desired.
Refrigerate until firm, about 4 hours. To cut, lift the bars out of the pan with the parchment paper, place on a cutting board, and cut into 9 bars. Store any extras in the refrigerator.