Treacle sponge roll with banana and cream

Ingredients

• 4 eggs, at room temperature
• 1/2 cup (110g) caster sugar, plus 1/4 cup extra
• 1 teaspoon vanilla extract
• 1/2 cup (75g) self-raising flour
• 30 gram butter, melted, cooled
• 2 teaspoon treacle, plus 1 tbsp extra
• 3/4 cup (180ml) thickened cream, whipped, to serve
• 1 large banana, thinly sliced