Heat 1 cup the heavy cream in a saucepan over low heat. Add the chocolate chips to the pan and stirring regularly, heat until the chocolate is fully melted. Remove from heat and allow too cool.
Using an electric mixer, beat erythritol and egg yolks together until pale and thick.
Add the egg mixture into the cooled chocolate and mix to combine. Return the pan to low heat and stir continuously until it thickens, about 1 minute. Do not allow the mixture to come to a bubble or it will break. Pour the mix into a bowl and leave to cool.
Using an electric mixer, whip the remaining 3/4 cup of heavy cream until thick and stiff peaks form. Fold the cooled chocolate mix, along with the almond butter and vanilla extract into the whipped cream. If the mixture is too thick, thin out with 2 to 3 tablespoons of unsweetened almond milk.
Pour the ice cream mixture into an ice cream maker (I use and love this one) and process according to the manufacturers instructions. This could take 15 to 45 minutes, depending on the ice cream maker being used.
Once the ice cream is done, transfer it to a large freezable container, like the loaf pan pictured. Fold in the brownie chunks and freeze for 1 to 2 hours, or until desired consistency is reached.
Once you remove the ice cream from the freezer, allow it to sit on the counter to soften just slightly before enjoying.