In the bowl of your stand mixer, fitted with the paddle attachment, cream the cream cheese and sugar, about 3 minutes. Scrape down the sides and add the sour cream, half-and-half, and 1/4 cup rumchata. Beat until combined over low speed.
Spoon a layer of the mixture into 8 pop molds or small cups (I find the Dixie cups with wax coating on the inside work great for these!). Place in freezer and let set for 2 hours. (Cover and refrigerate the remaining cream cheese mixture).
Mix the dulce de leche and remaining 2 tbs rumchata in a bowl. Spoon 2/3 of it into a ziplock bag and snip the corner off. Take the pops from the freezer and squeeze a layer of dulce de leche on each. Add a pop stick and top with the remaining cream cheese mixture. Place in freezer until set, 4 to 6 hours longer.
When ready to serve, dip the pops into the remaining dulce de leche mixture and then roll in crushed cereal. Serve immediately.