Dutch Process Cocoa Powder has a more neutral chocolate taste than natural cocoa powder. It is rich and some tasters say it has a bit of earthiness to it.
Dutch-processed or alkalized unsweetened cocoa powder is treated with an alkali to neutralize its acids. Because it is neutral and does not react with baking soda, it must be used in recipes calling for baking powder, unless their are other acidic ingredients in sufficient quantities used. Alkali reduces the acidity and raises the pH. The alkali brings out richer brown or red notes
To convert a cake recipe that uses bittersweet or semisweet chocolate to one using cocoa: Substitute 1 tablespoon plus 1 3/4 teaspoons of cocoa, 1 tablespoon plus 1/2 teaspoon granulated white sugar, 1 1/2 teaspoons unsalted butter for every ounce of bittersweet or semisweet chocolate. Also, dissolve the cocoa in at least 1/4 cup hot liquid to bring out the cocoa's full flavor