1.Pre-heat the oven to 300 degrees F and line 2 standard muffin tins with cupcake liners.
2. Place Do-si-dos in a food processor and blend until the mixture resembles fine crumbs.
3. Mix with 1/4 cup of melted butter to make a crust.
4. Press 1 scant tablespoon of crumbs into the bottom of each cup.
5.Press down using the back of a wooden spoon. Bake for 6-8 minutes or until lightly browned. Let cool.
6. Stir together the cocoa and rest of the melted butter (1/4 cup).
7. Beat 3 8oz. packages of cream cheese until fluffy. Add the cocoa and butter mixture.
8. Gradually mix in the sweetened condensed milk. Lightly mix the egg and vanilla, then add to the cream cheese mixture until combined well. Spoon into cups (about 3/4 full). Bake 30 - 35 minutes or until set. Cool.
9. For the ganache, beat the rest of the cream cheese and confectioners' sugar with a mixer on medium speed. Add salt, then peanut butter, then vanilla.
10. Add the cream and blend well. Chill the mixture in the refrigerator for an hour. Once the cheesecakes are completely cooled, pipe the ganache onto the cheesecakes.
11. Place a Tagalong cookie (that has been cut in half) in the center. Keep the cheesecakes chilled until ready to serve.