In a medium saucepan, combine 1 cup of raspberries, 1 cup of diced peaches, 1 cup of sugar, and 1 cup of water. Heat over medium heat, stirring gently until it starts to simmer (about 5 minutes).

Remove from heat and strain the mixture using a fine mesh strainer into a bowl, pressing to extract syrup.

While the syrup cools, brew your choice of black or green tea according to package instructions (190°F for 3–5 minutes). Allow to cool completely.

In a large pitcher, mix the cooled iced tea with the prepared fruit syrup (start with 1 cup of syrup per 4 cups of tea). Stir well to combine.

Ladle your Peach Raspberry Iced Tea into glasses, garnish with fresh berries or a slice of peach, and serve immediately.