In a medium bowl, combine the mascarpone cheese, orange juice, orange zest, and sugar. Mix gently until smooth, fluffy, and fully combined. Do not overmix.
If using, stir in the Cointreau just until incorporated.
Divide the crumbled speculoos cookies evenly between three coupe glasses, creating the base layer.
Spoon the mascarpone cream over the cookie crumbs, smoothing the tops lightly.
Arrange the sliced strawberries on top in a circular pattern, slightly overlapping for a polished look.
Serve immediately, or refrigerate for up to 2 hours before serving.