Mix egg yolk, almond flour, oat milk, and honey well. (If you have vanilla essence, add 3-4 drops.)
Simmer slowly over medium-low heat. (Wait until it thickens gradually without boiling vigorously.)
Let it chill in the refrigerator for about 30 minutes.
Mix Greek yogurt into the cooled mixture, then add sliced banana and soft egg biscuits and mix.
Refrigerate for 1-2 hours to set, then serve.