Preheat the oven to 180°C (350°F) and prepare a bundt cake tin with melted butter and a dusting of flour.
Add the soft butter and sugar to a bowl of a stand mixer fitted with a paddle attachment. Beat at medium-high speed until creamed, about 3 minutes.
With the mixer running at medium speed, add the eggs to the creamed butter and sugar mixture one at a time, scraping down the sides of the bowl with a rubber spatula between each addition.
Add the vanilla and beat again.
Mix together the mashed bananas and sour cream.
Sift together the flour, baking powder, and salt into a large mixing bowl.
Add the dry and wet ingredients to the cake batter by alternating between them, starting with the flour mixture and ending with the sour cream.
Pour the cake batter into the prepared pan and smooth over the top with an offset palette knife. Bake the cake in a preheated oven for 45 minutes or until it is golden brown and a cake tester inserted into the center of the cake comes out clean. Allow the cake to cool in its tin for 20 minutes before turning it onto a cake plate.
To make the sauce, place the caramel and ideal milk in a small saucepan set over medium to low heat. Using a whisk beat the mixture until the lumps have disappeared.
Remove the sauce from the heat and stir in the toasted pecans. Pour the sauce over the cake. Slice, serve, and enjoy.
Notes
You will need about 2 large ripe bananas for this recipe.
Ensure you have prepared the bundt cake pan properly so that it doesn't stick.
To make this banana cake nut-free, leave out the pecans when making the sauce.