Banana and Caramel Roulade

Ingredients

For the cake:

4 large eggs

1 cup granulated sugar

1 cup all-purpose flour

1 teaspoon baking powder

1 teaspoon vanilla extract

a pinch of salt

For the filling:

2 ripe bananas, mashed

1/2 cup caramel sauce

For the topping:

1/2 cup caramel sauce

1 sliced banana

1/2 cup walnuts, toasted and caramelized

Powdered sugar for dusting (optional)