In a large saucepan, whisk 1 ¼ cups half-and-half, sugar, cornstarch, almond paste and salt together until combined. Cook over medium heat, whisking frequently until mixture thickens, almond paste dissolves and mixture comes to a boil, about 3-5 minutes. Remove from heat.
In a large bowl, whisk remaining half-and-half and egg together until combined. Pour hot half-and-half mixture into egg mixture, whisking constantly to temper the eggs. Return half-and-half mixture to saucepan. Bring to a boil over medium-high heat, whisking constantly, until mixture thickens, about 2-3 minutes. Remove from heat and whisk in butter, 1 cube at a time, until completely combined and emulsified.
Place saucepan in a large ice bath to cool half-and-half mixture. In a large bowl, whisk heavy cream until stiff peaks form, about 1 minute. Gently fold whipped cream into half-and-half mixture until just combined. Cover with plastic wrap and refrigerate until chilled, about 1 hour.
Meanwhile make the crepes by combining milk, flour, eggs, salt, melted butter and sugar in a blender. Blend until smooth and aerated, about 15 seconds. The crepe mixture can be used immediately or refrigerated for up to 2 hours.
While almond cream is chilling, heat the Le Creuset Crepe Pan over medium heat for 5 minutes. Lightly grease the pan with additional melted butter. Add enough crepe batter to coat the bottom of the pan, about 3 ounces. Use the wooden rateau to evenly spread the batter across the pan.
Cook the crepe until the top has bubbles and is set, and the bottom is lightly browned, about 1-2 minutes. Using a wooden spatula, gently release the crepe from the pan and flip. Cook on the other side for 1 minute longer.
Remove the cooked crepe from the pan and place on a piece of parchment. Repeat with the rest of the batter, stacking the crepes, with parchment in between each one. Allow crepes to cool completely at room temperature.
To assemble the cake, place 1 crepe on a cake stand or large plate. Cover with about 2-3 tablespoons of the almond cream. Repeat layering with the remaining almond cream and crepes. Chill the cake for at least 30 minutes. When ready to serve, spread the blueberry curd over the top of the cake. Slice and serve.