In the bowl of a stand mixer fitted with the whisk attachment, combine the heavy cream, mascarpone, and Biscoff spread. Whip on medium speed until soft, fluffy peaks form. Add the sweetened condensed milk and whip briefly, just until the mixture is fully combined and smooth.
Gently fold in the crushed cookies using a rubber spatula, being careful not to deflate the mixture. Transfer the ice cream base to a piping bag.
Place silicone popsicle molds on a flat baking sheet for stability. Pipe the ice cream mixture halfway up each mold. Pipe a small amount of Biscoff spread into the center of each, then fill to the top with more ice cream mixture. Smooth the surface with a small offset spatula. Insert wooden popsicle sticks and freeze for at least 8 hours, or overnight, until completely firm.
Once frozen, carefully unmold the bars and place them on a parchment-lined baking sheet. Return to the freezer while preparing the first coating.
Melt the Biscoff spread in a wide, microwave-safe cup or bowl in 30-second intervals, stirring between each, until completely smooth and pourable. Working quickly, dip each bar into the melted spread, letting excess drip off. Return each coated bar to the baking sheet and freeze for 2 hours, or until fully set.
For the second coating, combine the chopped chocolate and canola oil in a microwave-safe bowl. Microwave in 30-second bursts, stirring well between each, until the chocolate is fully melted and smooth. Stir in the crushed cookies. Transfer the mixture to a tall, narrow glass or cup.
Remove the bars from the freezer and dip each one into the chocolate mixture. Let the excess drip off, then place the bars back onto the parchment-lined baking sheet. Freeze until the coating is fully set and the bars are firm. Serve directly from the freezer.