Delicious Blueberry Banana Bread with Dark Chocolate Chips

2 large ripe bananas(290 g without peel)
75 ml vegetable oil(1/3 cup)
1 teaspoon vanilla extract
50 g sweetener(stevia/or your choice) 1/4 cup
170 g flour(1 1/2 cups)
1 teaspoon baking powder
baking soda
125 g blueberries/ 4.4 oz
1 tablespoon chocolate chips
1 banana for decoration (optional)
chocolate chips for decoration(optional)
bake 35-40 minutes at 180°C/ 360°F