When I was in the Boy Scouts there was a time someone brought donuts to a meeting, and in particular, an orange glazed donut that looked as if it could fluoresce in the dark. It had more orange flavor than an orange itself.
This is almost a stab in the dark because it has been so long since I've eaten a "Triangle" as they were called, but since it was a Dutch/German enclave within a Shiawassee (Native American) settlement, my guess would be that they used a Bavarian cream base, but instead of using plain granulated sugar, they used maple sugar. In a traditional Bavarian cream you have the following approximate proportion of ingredients:
250 mL heavy cream
250 mL whipped cream (500 mL whipped cream for the Triangle)
45 mL cold water
2 mL vanillin
4 egg yolks
200 g granulated sugar (maple sugar for the Triangle)
14 g gelatin
Dissolve the gelatin in the cold water. Warm up the heavy cream and vanillin together. Beat the egg yolks and sugar together. Pour the warm cream mixture into the egg mixture while whisking. Bring the temperature of the combined mixture back up again and keep it warm until it's thick enough to heavily coat a spoon. Mix in the gelatin water. Cool the mixture as rapidly as possible (using refrigerator, ice bath, or both). Fold in whipped cream.
In the case of the Triangle cream, I think they used twice as much whipped cream because it had a light flavor and an even lighter texture. It had the consistency midway between a custard and a fluffy whipped cream.