Longer version: Dutch cocoa is cocoa that has been processed with alkalai. This raises its pH from around 5.5 to about 7, making it almost neutral. Unless your recipe calls for leavening, it doesn't matter whether you use regular or Dutch; many people prefer Dutch cocoa because it is smoother (though some will say smoothness sacrifices deeper chocolate flavor). It really is a matter of taste, and you should use whichever one you want, unless you are working with pastry. In this case, the less acidic Dutch cocoa is usually preferred. An eGullet pastry person can probably advise you better than me.
Based on the above, is it safe for me to assume that I can use either dutch-process or regular (Hershey's) cocoa for a Chocolate Pound Cake
recipe, the ingredients of which are:
1 cup unbleached all-purpose flour
1/2 cup unsweetened cocoa powder
Pinch of sea salt
4 large eggs, at room temperature, separated
1 cup granulated sugar
2 teaspoons vanilla extract
14 tablespoons unsalted butter, at room temperature
I have both types of cocoa, though I have more dutch-process than regular so I'd rather use dutch-process.