A type of biscuit (cookie) which is traditionally made from one part white sugar, two parts butter, and three parts oatmeal (although plain white flour is common today). Shortbread is so named because of its crumbly texture. Shortbread is traditionally formed into one of three shapes: one large circle, which is divided into segments as soon as it is taken out of the oven; individual round biscuits (“Shortbread Rounds”); or a thick oblong slab cut into “fingers.” It is made from a stiff dough that retains its shape well during cooking. The biscuits are often patterned, usually with the prongs of a fork before cooking; sometimes they are then sprinkled with more sugar while cooling. Shortbread is also sometimes shaped in stars and other shapes for special occasions.
Preheat oven to 350 F. Cream together butter, icing sugar, vanilla and salt. Gradually add cornstarch and flour. Whip with an electric mixer until fluffy. Place into a cookie press and press out cookies on cool baking sheet. Decorate with candied cherries or dragees if desired. Bake 12-15 minutes. Let cool for 2 minutes on baking sheet, then remove to wire rack to cool completely. Store in an airtight container at room temperature.
In a large mixing bowl beat the butter, sugar, lime juice, salt, and one half the lime zest (1-1/2 teaspoons) until light and fluffy. Stir in the rice flour, then all-purpose flour, beating only enough to incorporate. The dough will be very soft. Divide dough in thirds. Spoon each portion onto waxed paper or plastic wrap and form a log about 14 inches long and 1-1/2 inches in diameter. Fold the paper over the log, then roll with your palms until smooth. Twist ends of the paper and refrigerate or freeze until firm, 1 to 4 hours.
To make the lime sugar, place sugar and remaining zest in a blender or coffee mill and whirl until zest is very finely minced and sugar is lightly colored, about three minutes. Strain mixture through a fine sieve, discarding any bits of peel that remain. Set aside.
Preheat oven to 300 F. Slice chilled dough into rounds about 1/4 inch thick. Place 1 inch apart on ungreased baking sheets. Lightly butter the bottom of a flat-bottomed glass and dip into the lime sugar. Press lightly onto tops of cookies, dipping the glass into the sugar mixture before pressing each cookie to prevent dough from sticking. Bake 15 to 20 minutes, until light golden. Cookies will be fragile: allow to cool five minutes on baking sheets before removing with a spatula to cool completely on wire racks.
Preheat oven to 300 F. In heatproof bowl over saucepan of hot (not boiling) water, melt chocolate, stirring occasionally. Remove from heat and let cool. Meanwhile, in bowl, beat butter with sugar until fluffy. Stir in chocolate and vanilla. Add flour and salt; stir until blended. Mix in chopped crystallized ginger. Divide into 4 equal parts and chill 2 hours or until firm. Turn onto lightly floured work surface and roll out to 1/4″ thickness. Cut with cookie cutters and place cookies on baking sheets lined with parchment paper. Bake 30 minutes or until firm to the touch. Remove from oven and let cool for 2 minutes, then remove to wire racks to cool completely. Store in an airtight container at room temperature.