Blend the thawed mango chunks, granulated sugar, and lime juice in a blender until completely smooth. Transfer to a bowl and refrigerate for 15 minutes to thicken slightly.
Open the chilled coconut cream cans and scoop only the thick white cream into a large mixing bowl, leaving any liquid behind. Add powdered sugar and vanilla extract.
Beat the coconut cream mixture with an electric mixer on medium-high speed until soft peaks form, about 2-3 minutes. Be careful not to overbeat.
In a separate clean bowl, whip the heavy cream to stiff peaks, about 3-4 minutes. Gently fold the whipped cream into the coconut cream mixture until just combined and no streaks remain.
Spread a thin layer of mango puree in the bottom of a 3-quart trifle bowl or glass serving dish.
Layer one-third of the pound cake cubes over the mango, pressing gently against the sides for visual appeal.
Spread one-third of the coconut cream mixture over the cake layer, smoothing gently to the edges.
Repeat the layering two more times: mango puree, cake cubes, coconut cream, ending with a final coconut cream layer on top.
Cover and refrigerate for at least 4 hours or up to 24 hours to allow flavors to meld and cake to soften.
Just before serving, sprinkle toasted coconut over the top and garnish with fresh mango slices and mint leaves if desired.
