Place the flour and the baking powder into a large bowl. Using your hands, rub the butter through the flour until you have a breadcrumb consistency, making sure not to overwork the flour. Crack both the eggs into a measuring jug, add the buttermilk, salt , pepper and mustard powder. Whisk together with a fork. Gradually add a bit a time into the flour mix, combining as you go until the mix starts to form a dough. At this point pour the mix onto a clean surface and
Bring all the dough together. You may not need to use all the wet ingredients. Make sure just to bring the ingredients together and not to overwork the mix. Roll out the dough to about 1 1/2 inches thick. Using roughly a 6 centimeters cutter, or a slightly bigger one if that's what you have, cut out as many scones as possible. Bring the remaining dough back together and repeat until the dough is used.
Using a pastry brush and the left wet ingredients, brush the top of the scone. Place on a lined baking tray and place in the oven for 15-18 minutes until golden and cooked through.