2/3cup black cocoa or Dutch-processed cocoa powder
1 1/2cups flour, all-purpose
Filling Ingredients
1 1/2cups powdered sugar
6 tablespoons vegetable shortening
1/2 teaspoon vanilla extract
3 tablespoons corn syrup
Instructions
To make the cookie dough: in a stand mixer with the paddle attachment, cream the butter and sugar together for 3 minutes until light and fluffy. Add salt, egg, and vanilla, and mix to combine. Then add the cocoa powder and flour, and mix until just combined.* Flatten the dough into a disk and chill for at least 20-30 minutes.
To bake the cookies: preheat the oven to 300 °F. On a surface liberally dusted with cocoa powder, roll the cookie dough to ⅛” thick or thinner. Use a small circle cookie cutter (approx. 1.5 to 1.75-inch diameter) to cut circles from the dough, and transfer them to baking sheets lined with parchment paper. If desired, stamp patterns on the cookies by pressing down with a cookie stamp to indent.* Bake the cookies for about 16-18 minutes, and let them cool on the baking tray or transfer to a wire rack.
To make the oreo cream filling: in the bowl of a stand mixer or a large bowl, combine all ingredients together and beat until smooth.
To form the Oreos: place about 2 teaspoons of filling in the center of one cookie (the flat side). Top with another cookie of the same size and squeeze gently until the filling is spread almost to the edge.
Notes
The dough should be stiff but should hold together when pressed. If the dough is too crumbly and hard to work with, add cold water 1 tsp at a time until it holds together.
If using cookie stamps, dust them liberally with cocoa powder to prevent sticking.