Leche flan with coffee caramel

Ingredients

• 10 eggs yolks (i used duck eggs)
• 2 cans 370ml evaporated milk
• 1 can 300ml sweetened creamer ( or condensed milk)
• 1 tsp vanilla
• 1/2 tsp calamansi juice ( i wonder where the lemons are, the grocery ran out of it. But instead of lemon rind, i used calamansi juice to remove the slight pungent smell and taste of the eggs. and it makes the flan smoother)
• brown sugar, about 1 cup
• 1/2 to 1 tsp coffee, or as preferred