Raspberry Sauce

In medium saucepan over moderate heat, stir together raspberries, powdered sugar, and lemon juice. Heat, stirring often, until raspberries begin to release juice. Raise heat to moderately high and simmer, stirring occasionally, until slightly thickened, about 1 minute. Strain through fine-mesh sieve, pressing on solids to extract all liquid. (Sauce can be made ahead and refrigerated, covered, up to 1 week.)