Prepare the pan: Line an 8x8 cake pan with parchment paper, keeping 1-2 inches of excess on all sides (this is helpful if you prefer to lift the tiramisu out of the pan to get clean cuts when slicing).

Whip the cream: In a large mixing bowl with an electric mixer, whip the heavy cream until it's light and fluffy and stiff peaks form. Keep chilled in the fridge until ready to use.

Make coffee mixture: In a shallow bowl, mix together the coffee, 1 tablespoon vanilla, ½ teaspoon espresso powder, and 2 tablespoons of the powdered monk fruit sweetener. Set aside.

Mix mascarpone: In a separate large bowl with a hand mixer or stand mixer, beat together the softened mascarpone and cream cheese for 1-2 minutes on medium speed to mix. Add in the remaining 1 cup of powdered monk fruit sweetener and mix, just until it is incorporated.

Flavor mascarpone mixture: Add 2 tablespoons of the coffee/vanilla/espresso mixture (set the rest aside), 1 teaspoon vanilla extract and 1 teaspoon espresso powder to the mascarpone cream. Mix until well combined.

Fold: Using a rubber spatula, fold the whipped cream into the mascarpone mixture.

Assemble the keto tiramisu cake: Set the shallow dish with the coffee mixture next to your prepared pan. Dip each ladyfinger (or sponge cake piece) in the coffee quickly, then place it at the bottom of the pan to create the first layer. Repeat until the entire pan is covered in ladyfingers. Spread half of the cream mixture on top. Create a second layer of coffee-dipped ladyfingers on top of the mascarpone layer. Top the ladyfingers with the rest of the mascarpone filling and spread it evenly across the top.

Dust with cocoa powder: With a fine-mesh strainer or sifter, dust the top of the tiramisu with cocoa powder.

Refrigerate: Transfer the tiramisu to the refrigerator to chill for 4-5 hours, preferably overnight. It will firm up and the flavors will intensify.

Serve: When it's time to serve, you can use a spoon to dig right in and scoop out servings, or use the parchment paper "wings" to gently lift the cake out of the pan to easily cut it into square slices.