Hugh Fearnley-Whittingstall's honey and peanut butter booster bars recipe

I spent a long time tweaking and twiddling with this recipe before putting it into River Cottage Every Day and I am now very pleased with it. These fruity, nutty, oaty slabs are the perfect antidote to those dubious "energy bars" that seem to be ubiquitous these days. Makes 16 125g unsalted butter 150g soft brown sugar or light muscovado sugar 125g no-sugar-added crunchy peanut butter 75g honey, plus a little more to finish Finely grated zest of 1 orange Finely grated zest of 1 lemon 200g porridge oats (not jumbo) 150g dried fruit, such as raisins, sultanas and chopped apricots, prunes or dates, either singly or in combination 150g mixed seeds, such as pumpkin, sunflower, poppy, linseed and sesame Preheat the oven to 160C/gas mark 3. Grease and line a baking tin, about 20cm square. Put the butter, sugar, peanut butter, honey and grated citrus zests in a deep saucepan over a very low heat. Leave until melted, stirring from time to time. Stir the oats, dried fruit and three-quarters of the seeds into the melted butter mixture until thoroughly combined. Spread the mixture out evenly in the baking tin, smoothing the top as you go. Scatter the remaining seeds over the surface and trickle with a little more honey. Bake for about 30 minutes, until golden in the centre and golden-brown at the edges. Leave to cool completely in the tin (be patient – it cuts much better when cold), then turn out and cut into squares with a sharp knife. These bars will keep for 5-7 days in an airtight tin. • This is an edited excerpt from River Cottage Every Day by Hugh Fearnley-Whittingstall (Bloomsbury, £25). © Hugh Fearnley-Whittingstall 2011. Buy a copy for £20 from the Guardian bookshop