Flex layout to change order of blocks on mobile view

The image below illustrates what I am trying to achieve. I currently have the two column flex layout on the desktop view (as shown below on the left), but I cannot achieve the ordering on the right for the mobile view. Currently on the mobile view one column is stacked on top of the other and I can only reorder the blocks within each column. Is there another layout/method I can use to achieve this?

On mobile, change the Display setting of each column to contents, and set the Order of each block within the columns accordingly.