Preheat the oven to 350°F and line a 12-cup muffin pan with paper cupcake liners.

In a medium bowl, combine the almond flour, 3 tablespoons granular sweetener, and melted butter, stirring until the mixture is evenly moistened and clumps together.

Divide the crust mixture evenly among the 12 liners and press firmly into the bottom of each cup to form a compact, even layer.

Bake the crusts for 5 minutes, then remove the pan from the oven and let the crusts cool while you prepare the filling.

In a large mixing bowl, beat the softened cream cheese and 1/3 cup granular sweetener together until smooth and creamy with no lumps.

Add the sour cream, lemon juice, and vanilla bean paste to the cream cheese mixture and beat until fully combined and smooth.

Add the eggs one at a time, mixing on low speed just until each egg is incorporated and the batter is smooth, without overbeating.

Divide the filling evenly over the cooled crusts, filling each liner almost to the top.

Return the pan to the oven and bake for 12 to 15 minutes, until the edges are set and the centers still have a slight jiggle when gently shaken.

Remove the pan from the oven and let the mini cheesecakes cool completely in the pan at room temperature.

Transfer the cooled cheesecakes to the refrigerator and chill for at least 1 to 2 hours, or until fully set.

Just before serving, place the cold heavy cream and powdered sweetener in a chilled mixing bowl and whip on high speed for about 3 minutes, or until stiff peaks form.

Remove the chilled mini cheesecakes from the liners if desired, then top each with a dollop or piped swirl of whipped cream.

Finish each mini cheesecake with fresh berries on top and serve chilled.