Step 1In a saucepan on medium-high heat, combine 2 cups of milk with the pineapple juice and bring the liquid to a simmer. Reduce heat to medium, add the piloncillo, cloves and cinnamon stick and simmer, stirring occasionally until the sugar has dissolved, about 8 minutes. Add the chocolate and continue simmering until chocolate is dissolved, about 5 minutes.
Step 2In the work bowl of a stand mixer fitted with the paddle attachment, mix the masa and remaining milk on medium/low speed until fully combined and smooth, 3 to 5 minutes. Once the chocolate has melted, slowly add the corn-milk mixture to the saucepan, whisking simultaneously. Increase the heat to medium-high and bring to a boil. Reduce the heat to medium-low and let the mixture simmer, whisking occasionally to avoid clumping, until thick like a milkshake, about 10 minutes.
Step 3Strain, preferably into a ceramic dish to maintain heat. Serve immediately.