Banana, maple and pecan cake

Method

1. Heat the oven to 170°C fan/gas 5. Grease the cake tins with oil and line with baking paper. Put the 200g pecans in an oven dish in a single layer and toast for 10 minutes, then remove, allow to cool and roughly chop. These will go into the cake batter.
2. For the candied pecans, toast the 100g pecans in a dry pan over a high heat for a few minutes until they release their aroma, then scatter the 50g sugar over them. Use a wooden spoon to turn the nuts over in the sugar repeatedly until the sugar melts and turns amber. Remove from the heat and scatter over a sheet of baking paper to cool. Once cool, break apart any that have stuck together and set aside.
3. In a large bowl, mash the bananas with a fork. Add the oil, sugar, maple syrup, eggs and yogurt and mix well. In a separate bowl, mix both flours with the bicarb, then add this to the wet ingredients and gently mix until there are no dry patches of flour left. Fold in the toasted pecans, then divide the batter between the 3 cake tins.
4. Level the tops with a spatula, then bake for 25-30 minutes or until a skewer pushed into the middle comes out clean. Leave to cool for 5 minutes, then turn out onto a wire rack to cool completely.
5. To make the buttercream, put the egg whites and 250g sugar in a bowl set over a pan of boiling water, ensuring the bowl isn’t touching the water. Use a balloon whisk or spatula to beat or whisk the mixture constantly until it reads 72°C on a thermometer and the sugar has dissolved. Remove from the heat and use an electric whisk to whisk the mixture until it achieves stiff peaks. Continue to whisk while gradually adding the maple syrup, then whisk at a low speed until the bowl is no longer warm to the touch.
6. Gradually add the butter in chunks whilst mixing at a medium-high speed. The mixture will get loose and wet, then turn clumpy – but keep going until it becomes light and velvety. This will take about 10 minutes. Transfer the buttercream to a piping bag.
7. To assemble the cake, pipe a small amount of icing on the base of your serving plate or cake stand and put a sponge on it (this secures it in place). Pipe neat peaks of buttercream all over the sponge, then gently put the second sponge on top. Add another layer of buttercream peaks, then top with the final sponge. Pipe the remaining buttercream in a ring on top, then generously heap the candied pecans in the middle.