Phyllo Triangle Pastries with Custard (Trigona Panoramatos) - My Greek Dish

Ingredients

• 14-15 sheets phyllo dough
• 200g butter, melted (7 ounces)
• 950g/ 33.5 ounces milk, divided in 700g/ 24 ounces and 250g/9.5 ounces
• 300g sugar (10.5 ounces)
• 1 tsp vanilla extract
• 3-4 egg yolks, depending on the size of the eggs
• 250g all-purpose flour (8.8 ounces)
• 50g butter, at room temperature (1.8 ounces)
• 1/3 of a cup heavy whipping cream (cold)
• 1 tbsp icing sugar
• 500g sugar (17.6 ounces)
• 400g water (14.1 ounces)