Sure! I threw blackberries into these delightful little hand pies because we had them on hand, and because I like a not-too-sweet dessert. If you use a different berry, strawberries, raspberries or blueberries would be lovely paired with the peaches. If you want to just stick with peaches, knock yourself out! Whatever you decide to do, just sweeten lightly before tasting the fruit. Peaches alone will be sweeter than peaches and blackberries combined. Test the fruit, then sweeten accordingly so they’re not too sweet. (Unless that’s your thing. And then, well, go wild.)