Rinse basil and dry thoroughly. It's important that the basil is dry.
Remove all the leaves from the stems and add to food processor.
Chop basil for a few seconds in food processor. You may want to add the basil in increments, processing for a few seconds before adding more.
Add 1/4 cup of olive oil and blend.
Carefully scrape sides with a spatula then add remaining oil and process again.
If the mixture looks too dry add more olive oil.
Remove blade of food process and ladle into ice cube tray.
Freeze for 24 hours then remove frozen cubes from tray.
Store in a container or mason jar or large freezer bag in the freezer.