Tear each date in half, and remove and discard the pit. (Start with 10 dates, add more if you'l like it sweeter.
Put the yogurt in the bottom of a blender canister, then add the pitted dates, vanilla, olive oil, frozen strawberries, and water. Increase blender speed gradually and blend on high speed until smooth, 1 to 2 minutes. Taste, and if you'd like it sweeter, add 1 or 2 more dates and blend again until smooth.
Pour into 4 serving glasses and serve. Garnish each glass with a strawberry half, if desired.
The smoothie can be kept in a covered container in the refrigerator for up to 3 days - stir before serving. It will lose its thick iciness, but still be just as tasty.
Makes about 4 cups (960 ml) of smoothie.
Notes
If you'd like a less sweet smoothie, or if your Medjool dates are very large, start with 8 dates and add more to taste, if desired.