Prepare and Roast Peaches: Preheat your oven to 375°F (190°C). In a medium mixing bowl, combine the diced peaches with the brown sugar, granulated sugar, cinnamon, nutmeg, and ginger. Drizzle in the melted butter and lemon juice, then toss gently to coat the fruit evenly. Spread the peach mixture in a single layer on a baking sheet or oven-safe dish. Roast for 14 to 16 minutes, or until the peaches are tender but still hold their shape. Remove from oven and allow them to cool completely.
Make the Biscuit Crumble: While the peaches roast, mix together the flour, brown sugar, cinnamon, and nutmeg in a small bowl. Pour in the melted butter, and use a fork or your fingers to combine until crumbly pieces form. Set this crumble mixture aside to be folded into the ice cream later.
Whip the Cream: In a large mixing bowl, beat the chilled heavy cream with vanilla extract and salt on high speed until stiff peaks form. This whipped cream will provide the creamy texture for the ice cream base.
Prepare Peach Purée and Combine: Remove about two-thirds of the roasted peaches (without the juices) and place them in a blender or food processor. Puree until smooth, resembling applesauce. Stir the sweetened condensed milk into this peach purée until fully combined.
Fold Ingredients Together: Gently fold the peach and condensed milk mixture into the whipped cream using a rubber spatula, blending carefully to keep the whipped cream airy. Then, fold in the remaining diced peaches and the cinnamon biscuit crumble, ensuring even distribution without deflating the mixture.
Freeze the Ice Cream: Transfer the ice cream mixture into a 9" x 5" loaf pan or similar freezer-safe container. Cover tightly with plastic wrap or a lid and freeze for at least 6 hours, or until firm. When ready, scoop and serve your creamy, peachy dessert!