Add remaining mixture to dry ingredients along with the raisins. Mix lightly with a fork until mixture clings together and forms a soft dough. Turn dough out onto a lightly floured surface and knead gently 5 or 6 times. Divide dough in half. Repeat with remaining dough.
Place scones one inch apart on prepared pan.
Pierse tops with the tines of a fork. Brush tops with reserved egg mixture. Bake for 15 to 18 minutes, or until golden brown. In a medium bowl, combine the flour, sugar, baking powder, baking soda, salt and orange zest. Cut in the butter with a fork or a heavy-duty electric mixer until the mixture resembles coarse crumbs.