Place chocolate chips in 1 cup microwave safe bowl. Melt chips in the microwave at half power for 2 minutes, or until melted, stirring after each 30 seconds. Add ½ c. Greek yogurt to melted chocolate chips. Add 1/8 c. sugar if desired. Place mixture in a Ziploc bag and snip about ½ inch of the corner off.

Repeat the same process with the peanut butter chips.

Pipe alternating layers of chocolate Greek yogurt mixture and peanut butter Greek yogurt mixture in the Popsicle molds. Tap on the counter top a few times to help get the air bubbles out of the popsicles.

Cover popsicles with lids and freeze for 4-6 hours or until firm.