In a medium bowl combine the flour with the baking powder and stir very well. You may sift them together to ensure perfect blending.

In a large mixing bowl beat with an electric mixer or whisk together the eggs with the sugar. Beat for 2-3 minutes to add some volume.

Add the sour cream, oil and vanilla, one by one. Whisk or beat with the mixer after each addition, until smooth.

Gradually add the flour mixture, folding it gently with a rubber spatula. If using a stand mixer use the paddle attachment at a low speed. Make sure no lumps remain in the batter but do not overbeat.

Gently fold the chocolate chunks.

Grease and flour very well a bundt pan. Place 1-2 tablespoon oil in the pan and 1 tablespoon flour. Use a kitchen brush to ensure no part of the inside of the pan has not been coated.

Pour the batter into the pan.

Bake for 25-30 minutes or until the top is golden brown and a toothpick inserted in the centre comes out clean.

Let cool until room temperature before removing the cake from the pan and serving.