Preheat oven to 350 degrees F and line your pan with parchment paper.

Melt the butter for 15 seconds in the microwave then use a hand mixer to combine the butter with the sweetener.

Add egg and vanilla to the bowl and mix well.

Combine the rest of the ingredients for the whoopie pies in the bow and mix for 2 minutes, making sure everything is combined.

Using a small scoop or teaspoon, make the cookies into the same size circular shapes. Make sure to leave 2 inches between cookies because they expand as they bake. You will either need to use two sheets or do 2-3 batches.

You will bake for 10-15 minutes depending on their size. They need to have brown edges and be cooked through.

When they are done, let them cool completely before adding filling.

For the filling, combine the butter and cream cheese until mixed well.

Add in confectioner's sweetener and the vanilla. Mix until filling is smooth.

Add in the crushed pecans.

To make the whoopie pies, take a teaspoon or more and place it on one side of the cookie. Then, grab another cookie and set it on top, creating the whoopie pie.