Strawberry Mousse in a Shortbread Crust

This is a beautiful "company cake." The buttery golden crust and creamy, light-pink filling make a lovely presentation, and your first bite will convince you that this recipe is a "keeper!"
Crust
1/2 cup (1 stick) butter
1/4 cup confectioners' sugar
1 cup King Arthur Unbleached All-Purpose Flour

Filling
1 quart fresh strawberries
2 tablespoons lemon juice
3/4 cup granulated sugar
2 packages unflavored gelatin
1/4 cup water
2 cups whipping cream
For Crust: Cream butter and confectioners' sugar till smooth. Work in flour with a fork, stirring to make a smooth dough. Pat dough into the bottom of a 9-inch springform pan, and prick all over with a fork. Bake at 350°F for 10 minutes, then reduce heat to 300°F and bake 20 to 25 minutes longer, until golden. Let cool completely.

For Filling: Puree 1 1/2 pints of the strawberries, reserving the remainder for garnish. You should have about 2 cups of purée. Blend lemon juice and granulated sugar into purée. Soften 2 packages unflavored gelatin in 1/4 cup water; warm over low heat till gelatin dissolves. Stir dissolved gelatin into berry purée, and chill until mixture begins to thicken. Whip the 2 cups of cream till stiff; fold into berry mixture. Pour over shortbread crust. Halve the remaining strawberries and arrange them, cut side down, around the edge of the mousse. Chill in refrigerator till set. Serves 8.