Place the vanilla ice cream, fresh strawberries, milk, and vanilla extract into a high-powered blender.
Pulse 3-4 times to break down the strawberries into smaller pieces without over-blending.
Blend on low speed for 15-20 seconds, stopping to scrape down the sides if needed. The shake should move slowly in the blender and look thick and creamy.
If the blender struggles to move the mixture, add 1 tablespoon of milk at a time, pulsing between additions, until it just barely blends smoothly.
Pour immediately into two chilled glasses and serve with thick straws or long spoons.
