Wrap cold butter in cling film and beat off with a rolling pin. Place all ingredients, except oil, in a mixing bowl. Blend on speed 1. The dough will be firm. Knead on speed 2 for 5-6 minutes, until gluten is moderately developed. Gradually, in portions, introduce the oil. Continue kneading on speed 2 until a smooth dough forms.
Leave the dough to ferment for 90-120 minutes. Make a punch after 45-60 minutes from the start of fermentation. You can make 2 punches if the dough does not seem to be kneaded enough.
Divide the dough into square pieces weighing 90 g. Flatten the pieces of dough and roll into tight cylinders. With your hands, roll each cylinder into a bundle 20-25 cm long. Roll it up like a donut, overlap the edges, secure with a short punch on the table. Lay on a damp cloth, then dip in sesame seeds.
Leave the simites to proof for 45 minutes. Bake after that for 20 minutes at 230°C. Simites should turn pale brown, with a crusty but soft crumb.