Place the strawberries, butter and icing sugar in a small mixing bowl. Mix until well combined. Transfer to a decorative bowl. Tent with plastic wrap and refrigerate butter until needed. (Can be made a day before needed.)
Combine the milk, eggs and vanilla in a medium to large bowl. Place the flour, sugar, baking powder and salt in another bowl and whisk to combine. Mix the dry and wet ingredients together until just combined. (Don’t worry about a few small lumps.)
Preheat the oven to 200 degrees F. Preheat a non-stick griddle to, or place a large non-stick skillet over, medium to medium-high heat. Lightly coat the surface with vegetable oil spray. Spoon small, 2" rounds of the batter (about 1 Tbsp.) on the griddle, leaving a 2" space between each pancake. Flip pancakes when a few tiny bubbles appear on top. Continue cooking until the centre of the pancake springs back when touched, about 1 minute. Set cooked pancakes on a heat-proof serving platter and keep warm in the oven until all are done. Serve pancakes with the strawberry butter.
Note: The butter needs to be quite soft to mix well with the strawberries. If yours is a little firm, zap in the microwave for a few seconds.