Easy Louisa's Tiramisu

This is my own original recipe, which I haven't made since last century, but I am going to make it today.

2 packages ladyfingers, or one sliced pound cake
1 small carton Cool Whip, or 1 pint whipped cream
1 cup sour cream
1 cup cold, strong coffee
2 Tbs. brandy, rum, or liqueur (Kahlua, for example)
1 package Jello flan mix
Powdered cocoa

Note: When I first developed this recipe, there was a product on the market called Jello Americana egg custard, which is what I used. Apparently that product has been discontinued (at least where I shop it has), but the custard mix in Jello flan is the same. So...

1. Prepare the custard in the Jello flan mix according to the instructions, and let cool to lukewarm.
2. Place half of the ladyfingers or pound cake slices on the bottom of an 8-inch square pan.
3. Mix coffee and liquor, and pour half of that mixture over cake.
4. Mix sour cream with Cool Whip or whipped cream, then mix that with the custard. Spread half of that mixture over the cake.
5. Repeat layers.
6. Sprinkle top with powdered cocoa.
7. Cover and chill 4 hours or overnight. That is, chill the tiramisu.