Mix together flour, brown sugar, allspice, orange peel, salt. Cut in butter until small crumbles and completely blended.
Press in half of the mixture into a greased 8 or 9" spring form pan.
Add soda to sour cream. Mix in vanilla and then pour into the remaining crumble mixture. Stir until just mixed.
In a stand mixer with whisk attachment, beat the aquafaba with the cream of tarter for ~ 3 minutes until firm peaks form.
Fold aquafaba meringue into the crumble mixture and pour into the pan on top of the pressed crumble layer.
Sprinkle with sliced almonds and bake 40-45 minutes at 350F.
Serve with the whipped orange topping.
For the whipped topping, whip cream until stiff, then stir in sugar, peel and liquor. Chill for ~ 1/2 hour to let the flavours develop.