If you're not using a pre-baked pie crust, bake your pie crust at 375℉ / 190℃ for 20 minutes, or until it turns golden brown.
Wild Blueberry Jam
Add the frozen wild blueberries and sugar to a medium sized saucepan. Zest the lemon into the pan, then add in 1 tbsp. of lemon juice.
Set the saucepan over medium heat, stirring occasionally until the mixture starts to simmer.
In a small bowl, mix together the corn starch and the remaining 1 tbsp. of lemon juice. Let the jam simmer for 2 minutes, then, while constantly mixing, stir the corn starch slurry into the jam.
Continue stirring until the jam thickens. Once the jam thickens, remove it from the heat and transfer it to a shallow bowl. Set the jam in the freezer while you make the ice cream.
No-Churn Mascarpone Ice Cream
Add the heavy whipping cream to a large mixing bowl. Beat with a hand mixer or with a stand mixer fitted with the whisk attachment, until stiff peaks form.
To a medium sized mixing bowl, add in the mascarpone, sweetened condensed milk, salt, and vanilla. Beat the mixture just until it's cohesive.
Pour the mascarpone mixture into the whipped cream. Gently fold the mascarpone mixture into the whipped cream until the mixture is cohesive.
Crumble ~½ of the pie crust into the ice cream and fold until well combined. Then add in ⅓ of the wild blueberry jam and do a couple of big folds to mix the jam into the ice cream.
Pour ½ of the ice cream into your prepared loaf pan. Dollop ½ of the remaining jam over the ice cream, and crumble ½ of the remaining pie crust over the top of the ice cream. Use a knife to gently swirl the jam and pie crust into the ice cream.
Repeat with the remaining ice cream, jam, and pie crust. Cover the pan with plastic wrap and set it in the freezer for at least 4 hours, or until the ice cream is firm.