1-Step 1: Preparing the Raspberry Sauce: Start by combining 12 ounces raspberries, 3 tablespoons granulated sugar, 1 teaspoon lemon zest, and 1 tablespoon lemon juice in a medium saucepan. Cook over medium-high heat for about 5 minutes until the raspberries break down into a sauce.

Next, mix 1 teaspoon cornstarch with 1 teaspoon water to make a slurry, then add it to the raspberry mixture. Cook for another minute until it thickens slightly. Strain the sauce through a fine mesh strainer to remove seeds and chill it completely this step is crucial for that smooth swirl in your homemade ice cream.

2-Step 2: Making the Ice Cream Base: Whisk 14 ounces sweetened condensed milk with 2 teaspoons vanilla bean paste or extract until well combined. In a separate bowl, whip 2 cups heavy whipping cream to stiff peaks using a stand mixer or hand whisk, being careful not to overwhip.

Gently fold one-third of the whipped cream into the condensed milk mixture first, then add the rest until smooth, leaving some small lumps for texture. This no-churn method makes it easy to enjoy raspberry swirl ice cream without a machine.

3-Step 3: Assembling and Freezing: In a 1-quart container, layer half of the ice cream base and dollop half the chilled raspberry sauce on top. Swirl it with a knife for that signature look, then repeat with the remaining base and sauce.

Cover the surface with plastic wrap, add parchment paper, and seal tightly with foil. Freeze for at least 6 hours before softening at room temperature for a few minutes to scoop. The total preparation time is about 6 hours 30 minutes, including chilling and freezing, which fits into easy homemade raspberry swirl ice cream routines.