Cut Butter (80 gram) into few pieces and place the butter in freezer.
Preheat oven to 200 degrees C (400 degrees F) or 180 degrees C (350 degrees F) if fan forced.
Sift All-Purpose Flour (115 gram), Baking Powder (2 1/2 teaspoon) and Salt (1/4 teaspoon) together in a large mixing bowl. Stir in the Oatmeal (115 gram).
In a small bowl, whisk Large Egg (1) with Buttermilk (46 gram) together. Set aside.
Remove butter from freezer. Add butter into the flour mixture and use pastry blender to cut the butter until it looks like breadcrumbs. (If you do not have a pastry blender, use knife). Add Brown Sugar (40 gram) and Raisins (50 gram) mixed well.
Add egg mixture and mix with a spatula with cutting movement until all come together. If the dough seems too dry, add a little more buttermilk, a teaspoon at a time. Using hand, roughly make dough into a ball. Place the dough in the fridge for 10 – 15 minutes.
Remove dough from the fridge. Turn it onto a lightly floured surface and roll it into a rectangle about ½ inch thick. Fold it into thirds like a letter. Repeat another time the same way. Roll the dough out to at least 1 inch (2.5cm) thick. Please do not roll it any thinner as we want to have well-risen scones.
Using a round cutter, cut scone from the dough. Please don’t twist it, just lift it up and push the dough out.
Place the scones on the lined baking tray, brush them lightly with buttermilk.
Bake in the preheated oven for 10-15 minutes, or until golden brown and well-risen. Remove from oven and cool on a wire rack.