Preheat oven to 350°F. For the Crust, mix flour, confectioners' sugar, thyme and salt in large bowl. Cut in butter with pastry blender or 2 knives until mixture resemble coarse crumbs. Reserve 1/3 of crumb mixture (about 1 cup). Pat remaining crumb mixture into greased foil-lined 13x9-inch baking pan. Bake 15 to 18 minutes or until crust is lightly browned. Remove from oven.
For the Filling, mix granulated sugar, flour, ginger and baking powder in large bowl. Add lemon juice, eggs and lemon peel; whisk until blended. Pour lemon filling over warm baked crust. Sprinkle reserved crumb mixture over top.
Bake 20 to 25 minutes longer or until filling is set and golden. Cool in pan on wire rack.
Sprinkle with confectioners' sugar or drizzle with Lemon Glaze, if desired. Cut into bars to serve.