Combine first 5 ingredients in a bowl; set aside. Combine 1/2 cup sugar and oil in a large bowl; beat at high speed of a mixer 2 minutes. Add yogurt, extracts, egg, and egg white; beat 1 minute. Add flour mixture; beat at low speed until well-blended. Fold in rind and currants.
Pour batter into a 9-inch springform pan coated with cooking spray. Bake at 350° for 25 minutes or until golden and cake springs back when touched lightly in center. Remove from oven. Pierce cake with a fork. Combine 2 tablespoons sugar and lemon juice; spoon over cake. Cool on a wire rack.