I believe I saw a chart on some EA page that had ~20 interventions ranked by cost-effectiveness related to improving school attendance in global development. These included free uniforms, merit scholarships for girls, etc. I can't remember where I saw it though, does anyone know where that chart is located?
We are planning to use this chart in our kick-off EA meeting at the University of Chicago.
I used these images for a slide show a few years ago, the original source being this report by CEA (page 6).
That might be old data though, this is the most up to date version on JPALs website.
You might be thinking of work by the Copenhagen Consensus
This isn't the thing you were looking for, but this report contains a similar graphic. This other report also has a good list of interventions (p. 35), though it only covers costs rather than cost-effectiveness.