Make the Batter: In a large bowl, combine the 150g glutinous rice flour, 30g cornstarch, 5g butterfly pea flower powder, and 25g granulated sugar. Stir until well combined.
Add 25g corn oil and 230g whole milk, and whisk until the mixture is smooth and free of lumps. Scrape down the sides of the bowl to make sure everything is fully mixed.
Cook the Mochi: Pour the batter into a non-stick pan and heat it over medium-low heat. Stir constantly to prevent it from sticking to the pan. As the batter heats up, it will thicken and turn into a dough-like consistency. Keep stirring for about 5-8 minutes, or until the dough becomes smooth and pulls away from the pan.
Stretch and Knead the Dough: Once the dough is ready, transfer it to a clean surface or bowl. Let it cool slightly until it's just warm enough to handle. Then, stretch and pull the dough with your hands to make it more elastic. Continue until the dough is smooth and shiny.
Add the Oreo Crumbs: Fold in the 35g crushed Oreo crumbs, making sure they're evenly distributed throughout the dough. Once mixed, roll the dough into a log shape and cut it into even pieces. Set aside for later.
Make the Sea Salt Milk Foam: In a clean bowl, pour 100-150g heavy cream. Using a mixer, beat the cream on low speed, gradually adding 2-3 tablespoons of sea salt condensed milk. Continue to beat until stiff peaks form, but be careful not to over-beat the cream.
Assemble the Mochi: Place the mochi pieces on a plate. Spoon or pipe the sea salt milk foam onto each piece, making sure to cover them evenly. Optionally, sprinkle more crushed Oreo crumbs on top for extra flavor and decoration.