Preheat the oven to 375°F. Set out two dozen muffin papers on the counter top. Place the water, liquor, and butter in small saucepan. Heat over high heat until the butter melts. Remove from the heat. Soak each wafer into the water mixture for 30 seconds, or until the edges are soft, turning once. Press into a mini muffin paper, and repeat.

Make the filling. Whisk the flour, sugar, cinnamon, flaxseed, and salt in a large saucepan off the heat. Add the milk gradually, stirring until smooth. Cook the mixture over medium-high heat, until it boils, stirring constantly. Transfer 1 cup of the liquid into a mug. Whisk in the egg yolks. Slowly mix the contents of the mug back into the liquid in the saucepan. Remove from the heat and stir in the vanilla and margarine. Cool 10 to 15 minutes. Place one banana slice on top of each Nilla, spoon a teaspoon of the filling on top then, and smooth with a rubber spatula. Transfer the cups to a mini muffin tin.

In a large bowl, beat the egg whites and cream of tartar with an electric mixer set on high speed until frothy. Add the sugar gradually. Continue beating the egg whites, until they hold a glossy peak.

Spoon a teaspoon of the meringue onto the filling, spreading the egg whites to the edge of the crust with the back of a spoon. To make decorative peaks for the top of the pie, touch the back of the spoon to the egg whites and lift up. Bake 6 to 8 minutes until the meringue topping is nicely browned. Remove the mini cream pies to a wire rack to cool completely, and repeat with remaining pies. Serve at room temperature or chill uncovered for 1 hour before serving.