Marble Bundt Cake with Chocolate Glaze

marblebundtcakesourcream A marble Bundt cake has both chocolate and vanilla pound cake batter layered together to make a two-toned, perfectly moist and classic sour cream pound cake. The marble cake's origins hail from Germany, where it is known as Marmorkuchen, a deeply beloved birthday standard. Think of your a favourite rich chocolate cake to divide it into vanilla and dark-chocolate parts.

Marble Pound Cake:
1½ cups Monk Fruit Sweetener with Erythritol (Granular) (300 g)
1½ cups butter, softened (339 g)
1 tsp. fine sea salt
1 Tbsp. pure vanilla extract
1 tsp. baking powder
5 large eggs
⅓ cup full-fat sour cream
1 cup + 2 Tbsp. cake flour (150 g)
½ cup cake flour (65 g)
⅓ cup Dutch process cocoa powder (50 g)

Chocolate Glaze:
1 cup Monk Fruit Sweetener with Erythritol (Powdered)
2 Tbsp. Dutch process cocoa powder
1 pinch fine sea salt
2 Tbsp. milk

Topping:
flaked sea salt

Preheat the oven to 350°F (180°C/160°C fan, Gas Mark 4). Grease and flour a 10 cup Bundt pan.

If your eggs aren’t at room temperature, set them in a bowl of warm water.

In the bowl of a stand mixer, beat together the sugar, butter, salt, powder and vanilla for a full 10 minutes, the mixture should be very light and fluffy.

With the mixer on low, one by one add the eggs, allowing time for each to fully incorporate before adding another.

Add the sour cream and beat to combine.

Divide batter in half (use a scale if you have it, it'll be around 500 g for each half).

To one half sift in 1 cup flour + 2 Tbsp. of cake flour (White).
To one half sift in ½ cup cake flour and cocoa (Black).

Layer the batter into the Bundt pan, alternating between the chocolate and the plain (you should get about 3 layers from each for a total of 6-7 layers, extras can be added on top).

Bake for 50-60 minutes, until you can press the top and it feels firm, or use a cake tester.

Let cool in the pan for 5 minutes then overturn onto a cooling rack.

Once completely cool, make the glaze by whisking all the ingredients together. If the glaze is thick, add a bit more milk, if it’s too thin, add more powdered sugar (or cocoa).

Spoon glaze on top of Bundt and sprinkle with flaked sea salt.

Cook's Notes:

This recipe is a lengthy but simple process: the butter and sugar need to be beat really, really well, then the eggs go in (one by one), beat again for awhile and then sour cream. Divide the batter into two and add just flour to one and a mix of flour and cocoa to another. Then you’ll layer the batters into a Bundt cake.
Most important: have EVERYTHING at room temperature. This enables the batter to blend easily together.
To get a moist pound cake you need to use the good fats, hence sour cream pound cake. Butter is a given, but adding sour cream will make for a richer, super moist and tender cake. In my experience, a sour cream pound cake is far and wide better than one made with milk or even heavy cream because it leads to a moist, melt-in-your-mouth bite.

Recipe Ingredients:

Butter: I used American style butter here. It should be unsalted so you can control the amount of salt added to the batter and it must be at a soft room temperature.
Sweetener: Reducing the sugar will affect the structure and texture (moisture level) of the cake.
Cake Flour: Cake flour is more finely ground than all purpose and made from a softer wheat. It gives this cake a super tender texture. If you can’t find it you can swap it for all purpose.
Cocoa: Dutch process cocoa has a richer flavour so it’s my preference for this cake.
Vanilla: Pure vanilla extract or vanilla bean paste. Use good quality.
Salt: Fine sea salt. Fine means it will dissolve better into the batter.
Eggs: Whole large eggs. Bring them to room temperature before you begin.
Sour Cream: Full fat, also bring it to room temperature before you begin.

Frequently Asked Questions:

How to soften butter quickly? My cheat way of doing this is popping butter (in it’s paper wrapper) in the microwave for 10 seconds or less. Never to the point of melting it, but just so that if I press it, it leaves an indentation.
Why do we beat pound cake batter so long? Most cakes need air beaten into them in order for them to rise, usually you’ll add baking soda or baking powder to make those air bubbles bigger so the cake rises in the oven. A classic pound cake has no leavening and so we’ll beat as much air as possible into it. That along with the eggs will help it rise and become tender.
Can I make substitutions for this marble pound cake recipe? No substitutions for the eggs, butter or sugar. If you cannot find cake flour, you may use all purpose flour (perhaps even swapping out a tablespoon of it for some cornstarch) and it’s possible a full-fat Greek yogurt would work here instead of sour cream, though I haven’t tried it.
How can I vary up the flavor in this pound cake recipe? This recipe yields a classic vanilla and chocolate cake but you can add some lemon or orange zest to it, or some spices (cinnamon! cardamom!) to jazz it up a bit.
How do I know when a pound cake is done baking? Use a cake tester or press your finger into the center; if it springs back and feels firm, the cake is done.
How to make a thick chocolate glaze, as pictured? Use less liquid and more powdered sugar. When you stir it with a rubber spatula, it should be stiff but still slightly pourable.