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Can you link or post the recipe in question? Did you change any of the quantities or substitute ingredients?
Some cakes are a bit crumbly. Are you certain this isn't supposed to be one of them?
Hi thank you very much actually it is not a crumbly cake let me give you the ingredients
Three-quarter cup butter and 3 ounces semi sweet chocolate 1 1/4 cup walnut one and a half cup sugar 1 cup all-purpose flour half a cup so unsweetened cocoa 1 1/2 teaspoon baking soda 1/4 teaspoon salt two large eggs 1 cup buttermilk let me know what you think
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I suspect it was over baked. In teaching, I find it's pretty common for people to be more concerned about under baking to the point that they over bake cookies, muffins and cakes. You can certainly use the toothpick method to test for doneness, but it is just as effective to lightly tap the top of the center. When it feels springy, but not soft, it is done. If you wait until it begins to pull away from the sides, it is overdone.