Preheat the oven to 180C/Gas4; Roll out the pastry and use it to line a 25cm loose-bottomed tart tin, lightly oiled; bake the pastry case blind
Peel the bananas and slice into rounds about 1cm thick; put into a bowl with the toffee sauce and orange zest and mix together gently, taking care not to break up the banana slices; pour into the pastry case
Whisk the egg whites until they form stiff peaks, then add the sugar in batches and continue to whisk until vey glossy; sift the cocoa powder, then lightly fold half of it through the meringue
Spoon the meringue over the pie, then dust with the rest of the cocoa and use a fork to swirl the top and form peaks
Bake in the preheated oven for 20-30 minutes until the meringue is golden; allow to cool for 10 minutes then remove from the tin and serve
8 servings