Salted caramel and chocolate cake

Chocolate sponge cakes

• 140 g butter plus extra to grease
• 200 g plain flour
• 280 g brown sugar
• 70 g Dutch cocoa powder
• 1 tsp bicarbonate of soda
• 200 g brewed coffee
• 70 g canola oil
• 2 eggs
• 150 g buttermilk
• 1 tsp natural vanilla extract

Cream and salted caramel filling

• 80 g unsalted butter cut into pieces
• 120 g double cream
• 50 g dark brown sugar
• 50 g caster sugar
• 50 g pure maple syrup
• 1 tsp vanilla bean
• 1 tsp sea salt
• 600 g whipped cream