Add eggs and sweetener to a bowl and lightly whisk to combine. Place over a saucepan of boiling water (to form a bain marie), and cook the mixture until the sweetener has dissolved and the temperature is warm.
Remove from the heat, then add in almond flour and brandy, if using. Set aside to cool.
Pour the heavy cream and vanilla extract into a stand mixer bowl and whisk until soft peaks form. Fold in the cooled egg mixture and the chocolate chips.
Line a loaf pan with plastic wrap and pour the mixture into the pan. Place in the freezer for at least six hours or overnight.
Remove from the freezer five minutes before serving, then use the plastic wrap to lift it out of the pan, flipping it over onto a serving plate. Garnish with toasted sliced almonds. Cut into slices and serve immediately.