Pour the water and sugar into a large bowl. Sprinkle the dry yeast on top and stir to combine. In another bowl, whisk together the flour and salt.
Pour the dry ingredients over the wet. Using a spatula or your hands, mix the ingredients together. The dough should be shaggy with no dry patches of flour. Cover and let it sit at room temperature for 30 minutes to rise.
Dip your hands in water. Starting from the side farthest from you, pull and stretch the dough from one side up and over towards you in the bowl, pressing the dough down. Turn the bowl 90 degrees and repeat this pulling/folding three more times.
On the baking sheet Spread the dough into a round or oval shape with 1-2 cm thickness. Squeeze and pop any air bubbles.
Brush dough round/oval with the cream. Using your finger tips, make indentations on the dough about 2cmfrom the edge to make a circle. Then dip your finger tips in the cream and make 3-4 deep indentation lines (don't tear dough) inside the circle indentation. Turn the dough 45° and repeat 3-4 indentation lines inside the circle indentation. You should have diamond shapes now. It doesn't have to be perfect!
Top with sesame seeds and or nigella seeds, and carefully lift and place the parchment paper with the dough on the baking sheet on the middle rack.
Bake in the preheated 250Cn for 18-20 minutes or until golden on top. Transfer to a wire rack to cool. Serve warm or cold.