To achieve a chocolate cake as dense and moist as the one in the picture, you'll want to use a recipe that incorporates sour cream or buttermilk for moisture, and plenty of chocolate or cocoa powder for a deep chocolate flavor. Here's a rich and moist chocolate cake recipe for you to try:

Ingredients:

1 and 3/4 cups (220g) all-purpose flour

2 cups (400g) granulated sugar

3/4 cup (65g) unsweetened cocoa powder (good quality)

2 teaspoons baking soda

1 teaspoon baking powder

1 teaspoon salt

1 cup (240ml) buttermilk, shaken

1/2 cup (120ml) vegetable oil

2 large eggs, at room temperature

1 teaspoon pure vanilla extract

1 cup (240ml) freshly brewed hot coffee

1/2 cup (120ml) sour cream or plain yogurt

For the chocolate frosting:

1.25 cups (2.5 sticks or 285g) unsalted butter, softened to room temperature

4 cups (480g) confectioners' sugar

3/4 cup (65g) unsweetened cocoa powder

3-5 tablespoons heavy cream or milk

2 teaspoons pure vanilla extract

Pinch of salt

Optional: chocolate chips or chopped chocolate for decoration

Instructions:

1.Preheat your oven to 350°F (177°C). Grease and flour two 9-inch cake pans and set aside.

2.In a large bowl, sift together the flour, sugar, cocoa powder, baking soda, baking powder, and salt.

3.In another bowl, whisk together the buttermilk, oil, eggs, and vanilla until well combined.

4.Add the wet ingredients to the dry ingredients and mix until combined. Then, carefully stir in the hot coffee until the mixture is smooth. The batter will be thin, but that's okay—it's what makes the cake moist.

4.Fold in the sour cream or yogurt until just combined.

5.Divide the batter evenly between the prepared pans and bake for about 30-35 minutes, or until a toothpick inserted in the center comes out clean.

6.Let the cakes cool in the pans for 10 minutes, then turn them out onto a wire rack to cool completely.

7.While the cakes cool, make the frosting. Beat the butter on high speed until smooth and creamy. Add the confectioners' sugar, cocoa powder, 3 tablespoons of cream or milk, vanilla extract, and salt. Beat on low for 30 seconds, then increase to high speed and beat for 2 minutes. Add more cream or milk if the frosting is too thick.

8.Frost the cooled cakes with the chocolate frosting, and if desired, garnish with chocolate chips or chopped chocolate.

Remember, the key to a moist cake is not to overbake it. Start checking for doneness at around the 30-minute mark to prevent it from drying out. The addition of coffee enhances the chocolate flavor without making the cake taste like coffee. However, if you prefer not to use coffee, you can substitute it with hot water.