Combine skim milk, nonfat powdered milk, carob powder, cinnamon, vanilla, and peanut butter in a blender.

Add the ripe banana to the blender.

Blend the ingredients until smooth.

With the blender running on high, add ice cubes one at a time through the lid opening.

Continue blending until the ice is fully incorporated and the shake reaches desired consistency.

Pour into a glass and serve immediately.