Add the strawberries, allulose and lemon juice to a small saucepan. Simmer over medium heat for 8 to 10 minutes, mashing as it cooks, until thick and jammy, then let it cool completely in the fridge.
Preheat the oven to 350°F. Mix the almond flour, melted butter, erythritol, cinnamon and salt until clumpy, spread on a lined baking sheet and bake for 8 to 10 minutes until golden, then let it cool and break into crumbs.
Beat the cream cheese, powdered allulose, vanilla extract, lemon zest and salt with 1/4 cup of the heavy cream until completely smooth.
In a separate bowl, whip the remaining heavy cream to stiff peaks. Gently fold the whipped cream into the cream cheese mixture in two additions until no streaks remain.
Spread one third of the ice cream base in a loaf pan, then dollop with spoonfuls of the strawberry swirl and sprinkle with crumble. Repeat the layers twice more.
Drag a spoon handle through the layers a few times to create a ripple effect, keeping some crumble on top.
Cover and freeze for at least 6 hours or overnight. Let it sit for 10 minutes before scooping.