Preheat the oven to 200°C.
In a bowl, sift together the flour, baking powder and baking soda, and keep it aside.
In another large bowl, add the condensed milk, buttermilk, vanilla extract, oil and both the sugars.
Give this mixture a good whisk by hand, until all ingredients are thoroughly mixed together.
Then add in the flour mixture and whisk again for about 1 minute, or until the flour disappears. Do not overmix
Fold through the grated carrots.
Pour this mixture into a baking tin or a cake loaf tin and tap several times to remove any air bubbles.
Bake at 200°C for 10 minutes and at 160°C for 30 minutes.
Leave it to rest for at least 10 minutes before demoulding, and leave it to cool completely at room temperature for 30 minutes before cutting it in pieces