Preheat oven to 400 degrees.
Spray a baking sheet with non-stick spray or line with parchment paper.
In a large bowl, mix the flour, baking powder, baking soda and salt.
Add the butter and cut it into the flour with a pastry blender or fork until it resembles course crumbs. You can also use a food processor for this and pulse until it resembles crumbs.
Add 1 cup of the shredded cheese and the diced jalapeno and mix into the flour.
Make a well in the center of the dry ingredients and pour the buttermilk into the well. Push the dry ingredients into the buttermilk and gently mix to combine. You should end up with a semi wet dough.
Turn the dough out onto a lightly floured counter or pastry mat and bring the dough together with your hands.
Roll out into a narrow rectangle, then fold the dough into thirds. (Fold one side into the middle, then fold the other side over top)
Roll the dough out again into a rough square (9x9 inches or so) just over ½ inch thick.
Cut the dough into quarters, then diagonally cut each smaller square into 2 pieces. You should end up with 8 triangles.
Place the triangles onto the baking sheet leaving at least an inch between them.
Top each scone with a tablespoon of the remaining cheddar and jalapeno slices.
Bake for 22-25 minutes until lightly golden brown. Remove to wire rack to cool.