Use a high-speed blender for a creamy, pudding-like texture.
Add all blended oat ingredients to the blender in order (milk first, oats last) for smooth blending.
Blend on high until the mixture is completely smooth, with no visible oat bits.
Divide the blended mixture evenly among 8 jars, seal, and refrigerate for at least 4 hours or overnight.
In a microwave-safe bowl, melt dark chocolate chips in 20-second intervals, stirring in between.
Stir melted chocolate with vanilla yogurt until smooth.
Spoon the chocolate frosting over chilled oats, cover, and refrigerate for another 4 hours. Enjoy chilled!