Step 1 – Use an electric beater to beat eggs and sugar until thick and pale, and a ribbon trail forms when beater is lifted. Fold in flour, ginger and cinnamon.
Step 2 – Spoon into a lined 24.5 x 31cm Swiss roll pan. Smooth surface. Bake at 200°C for 10-12 minutes or until a skewer inserted into centre comes out clean.
Step 3 – Quickly turn onto a clean tea towel. Remove paper. Starting at 1 long side, use the tea towel to roll up the hot cake. Cool, seam-side down, on a tray.
Step 4 – Beat mascarpone, cream, maple syrup and extra sugar on low speed for 1 minute. Beat on medium-high until it thickens slightly (don’t overbeat).
Step 5 – Once the cake is completely cool, unroll it carefully. Use a flat-bladed knife to spread 3/4 cup of mascarpone mixture evenly over the cake.
Step 6 – Roll up. Place, seam-side down, on a plate. Cover with remaining mascarpone mixture. Use the end of a knife to make a tree ring pattern on each end.
Step 7 – Make the toffee nut bark: Stir the sugar and water in a saucepan over low heat until the sugar dissolves. Increase heat to high, brushing down the side of the pan with a wet pastry brush to dissolve any sugar crystals. Bring to boil. Cook, without stirring, for 8-10 minutes or until golden. Remove from heat. Stir in the walnut. Pour over a lined baking tray, tilting to spread the toffee as thinly as possible. Set aside for 5 minutes to set.