Preheat the oven to 340°F.Grease a 10" x 5" x 3 ½" loaf pan and set aside. I used a small bundt and a small loaf pan or you can use a large bundt pan.In a large bowl, combine the sweeteners, eggs, butter, vanilla and banana pure.In a separate bowl sift: flour, baking soda, tonka or nutmeg, salt and baking powder. Pour the wet ingredients over the dry ingredients and mix together with a whisk until just combined.Pour the batter into prepared pan and bake until golden brown and a cake tester inserted in the center of the loaf comes out clean, about 1 hour and 10 minutes. Depending on the pan you choose. Bundt cakes bake faster. Cool on a baking rack, unmold. Allow to cool for 20 minutes before slicing.