1. Preheat oven to 350°F Grease a 9-inch square pan.
2. Stir together flour, baking soda, and salt. Stir in oats, bran and sugar, Work in butter with a fork until crumbly. press into pan.
3. Stir in mincemeat with peel and cinnamon. Spread over base.
4. Drain mandarin oranges, gently press into mincemeat.
5. Bake 40 minutes. Cool and refrigerate.