Crust: Cream butter and sugar in a mixing bowl with an electric mixer. Beat in egg and vanilla. Stir in dry ingredients. Cover and chill for at least 30 minutes.

Roll out or pat the sugar cookie dough into a 12-13" circle on a piece of parchment paper. Transfer to a cookie sheet and bake at 350° for 18-20 minutes or till golden brown around the edges. Cool completely.

Strawberry Glaze: Combine 2 cups of the berries with 1/2 cup of sugar. Let sit at room temperature for about 30 minutes.

Drain all of the juice from the berries and measure 1/2 cup. (If you don't have enough juice, you can add a little bit of water.)

Measure the cornstarch into a medium saucepan and slowly whisk in the strawberry juice mixture. Whisk till smooth. 

Add the berries and bring to a boil over medium heat, stirring constantly. Boil for at least 2 minutes, or until thickened. Remove from the heat and stir in the lemon zest.

Place the saucepan in a bowl or sink full of ice water to cool the mixture quickly. Stir occasionally.

Filling: Beat the cream cheese, powdered sugar, and vanilla till smooth.

Assemble: Spread the cream cheese mixture over the cooled crust. Next spread on the strawberry glaze mixture. Arrange the last 2 cups of strawberry slices on top.

Cut into wedges and serve immediately.