Cream margarine and sugar together in a large bowl by hand or with a mixer. Add eggs and mix thoroughly.

Add flour, baking powder, cinnamon and salt and stir until dough is formed.

Preheat oven to 375 and prepare baking sheet lined with parchment paper.

On a lightly floured surface roll out dough 1/4 inch thick. With a 3 inch cutter (I use a glass) cut out as many holes as possible. Fold up corners to form a triangle, leaving a nice empty hole in the center to fill afterwards.

Transfer hamantashen to baking sheet, place in the oven and bake for about 20 minutes, until golden brown. Cool and then using a spoon pour in some dulce de leche.

Heat milk and sugar in a saucepan over medium heat. Add vanilla and stir until sugar is dissolved. Add baking soda, stir and bring heat down to lowest setting, allowing to cook on a low simmer for about 2 hours, stirring every so often.

Once it turns brown and thickens a bit, strain through a strainer and store in the fridge until ready to use.