Preheat the oven to 400°F. Spray a 24-cavity mini muffin pan with non-stick spray. Set aside.
Place the all-purpose flour, baking soda, salt, and Dutch-process cocoa powder in a medium bowl. Then, using a whisk, combine the dry ingredients. Set the bowl aside until ready to use.
Place the Crisco shortening and unsalted Kerrygold Irish butter in a large bowl, and using an electric hand mixer, beat them together.
Add the granulated sugar and beat for about 2 minutes until light and fluffy.
Add the egg and vanilla extract and beat for about 2 minutes until light and creamy.
Add the dry ingredients to the wet ingredients and beat until well combined.
Using a small ice cream scoop, place about 2 tablespoons of dough into each of the wells of the prepared mini muffin pan. Then, using your fingers, press the dough down so that it fills the entire cavity.
Bake in a 400°F oven for 10-12 minutes, then transfer the pan to a wire rack when the cookie cups are done.
Immediately press a Rolo chocolate candy into the center of each cookie cup.
Allow them to cool for 10-15 minutes in the pan, then remove them from the pan and transfer to a wire rack to finish cooling completely.