Date and chestnut cake with pomegranate butterscotch

Name: Date and chestnut cake with pomegranate butterscotch
Prep time: 20 min
Cook time: 1 h 25 min
Total time: 1 h 45 min
Cuisine: European, Mediterranean, French
Ingredients: 300g fresh dates, pitted; 1 1/2 tsp bicarbonate of soda; 150g unsalted butter, softened; 300g brown sugar; 3 eggs; 1 tsp mixed spice; 150g chestnut puree (from gourmet food shops); 1/2 cup (50g) almond meal; 1 1/2 cups (225g) self-raising flour, sifted; Cooking oil spray, to grease; 2 x 240g cans peeled chestnuts (substitute fresh chestnuts); Pomegranate seeds and creme fraiche, to serve; 1 cup (250g) firmly packed brown sugar; 1 cup (250ml) pure (thin) cream; 200g unsalted butter, chopped; 2 cinnamon quills; 2 tbs pomegranate molasses