1
: Pulse all shortbread ingredients together in food processor until butter is the size of small peas. Press firmly into 9” (23 cm) square parchment paper-lined baking pan. Bake in preheated 350ºF (180ºC) oven for 20 minutes. Remove from oven, and reduce heat to 325ºF (160ºC).
2
: Beat all filling ingredients together. Pour over hot shortbread base and bake 30 - 35 minutes or until middle is almost set. Remove from oven and cool completely on wire rack. Chill if desired.
3
: To serve, cut into squares and garnish with a light dusting of icing sugar, lemon zest, berries and a sprig of mint. Can be served at room temperature or chilled.