Marble Babka 'Fluffy Twist of Vanilla and Chocolate'

Start by preparing the bundt pan. Take a pan with a capacity of about 2 liters. Using a pastry brush, thoroughly grease the entire interior, including the tube, with a thin layer of soft butter. Then, add a tablespoon of flour to the pan and, rotating the pan, spread it so that it covers the entire greased surface. Shake out the excess flour by tapping the pan on the countertop. Set the pan aside. Preheat the oven to 175°C (top and bottom heat, no fan). Make sure all the ingredients (butter, eggs, milk) are at room temperature.

In a large bowl, sift the all-purpose flour, baking powder, and salt. Sifting is very important as it aerates the dry ingredients, making the dough fluffier, and also removes any lumps. After sifting, gently mix everything with a whisk to evenly distribute the ingredients.

In a second, large bowl, place the soft butter and fine sugar. Using a hand mixer or a stand mixer with a whisk attachment, start beating the ingredients on medium speed. Beat for about 7-10 minutes. The mixture should become very light, almost white, and noticeably increase in volume. It should have the consistency of fluffy cream. This is the most important step for achieving a light cake.

To the whipped butter-sugar mixture, add the eggs one at a time. Crack one egg in and mix on medium speed just until it combines with the mixture. Only then add the next egg. Repeat this process with all four eggs. After adding the last egg, mix for about another minute. The mixture may look slightly curdled – don't worry, everything will return to normal once you add the flour.

Now you will alternately add the dry ingredients (flour with baking powder and salt) and milk. Reduce the mixer speed to the minimum. Add 1/3 of the flour mixture and mix briefly, just until combined. Then pour in half of the milk and mix briefly again. Repeat: add another 1/3 of the flour, mix, pour in the remaining milk, mix, and finally add the last portion of flour. Mix only until no dry ingredients are visible. Do the final gentle mixing with a spatula.

Divide the prepared dough into two equal parts. The easiest way to do this is 'by eye', transferring half of the dough with a spatula to another clean bowl. Try to ensure that both bowls have roughly the same amount of dough.

Add vanilla extract to the first bowl with the batter. Gently but thoroughly mix the mixture with a spatula, using an up-and-down motion to avoid losing fluffiness. This will be your light batter.

Sift dark cocoa into the second bowl with the batter. Just like with the vanilla mixture, gently mix the cocoa into the batter using a spatula until you achieve a uniform chocolate color. Stir patiently, but try not to do it for too long. The cocoa mixture will be slightly thicker than the vanilla one – this is normal.

In the prepared mold, start layering the batter alternately. Using two different spoons, place dollops of light and dark batter next to each other to create the first layer. Then, add dark batter on the light dollops and light batter on the dark ones. Continue this way until you use up all the batter. Finally, gently smooth the top with a spatula.

Take a long skewer or a spoon handle. Insert it into the batter and make 2-3 circular, wavy movements inside the mold, going through all the layers of the batter. This will combine the mixtures and create a characteristic marbled pattern.

Place the pan in the preheated oven at 175°C and bake for 45-55 minutes. After about 45 minutes, perform the toothpick test: insert a wooden skewer into the thickest part of the cake. If the skewer comes out dry (without traces of raw batter), the cake is ready. If there are crumbs on it, that's fine, but it should not be wet.

Remove the baked cake from the oven and place the pan on a cooling rack. Leave it in the pan for about 15 minutes. After that time, carefully turn the pan upside down and remove the cake onto the rack. Allow it to cool completely.

When the cake is completely cool, you can decorate it. The simplest way is to dust it with powdered sugar. Pour the powdered sugar into a small sieve and gently tapping the edge, evenly sprinkle the entire surface of the cake.