Cream the butter and granulated sugars together on medium speed until well combined. Beat in the egg, vanilla extract and strawberry jam. On the lowest speed setting, mix the dry ingredients to the wet until just combined.
In a mixing bowl, add 2 tablespoons of strawberry jam and ¼ cup (59 ml) of heavy cream to the powdered sugar. Mix until well combined. Taste and adjust. Add up to 2 more tablespoons strawberry jam if needed.