Peanut butter layer cake

Name: Peanut butter layer cake
Cook time: 1 h 15 min
Total time: 1 h 15 min
Cuisine: American
Ingredients: slightly salted butter 100g, softened; crunchy peanut butter 200g; light muscovado sugar 250g; large eggs 3; very ripe, black bananas 250g mashed weight (see tip, below); natural yogurt 125g; vanilla extract 1 tsp; self-raising flour 250g; baking powder 1 tsp; cinnamon 2 tsp; ground nutmeg 1 tsp; honey-roast peanuts a small handful, chopped for the top; slightly salted butter 330g, softened; smooth peanut butter 75g; icing sugar 650g, sifted; vanilla bean paste 2 tsp; milk 3 tbsp