Preheat oven to 400F. Line a baking sheet with parchment.
Grate your cold butter on the large holes of a box grater into a small bowl. Place in the freezer to chill. We want the butter to be frozen so that it does not melt when mixed in with everything. The butter flakes are what give the scones their light, crumbly texture.
In a large bowl, mix together the whole wheat flour, flour, oats, coconut sugar, baking powder, and salt.
In a medium bowl, whisk together the milk, vanilla, egg, and zest (if using) until smooth.
Add the chilled grated butter into the flour mixture and use your hands to mix it in with the flour. If any large chunks remain, break them up with your fingers.
Pour the wet into the dry ingredients and use a rubber spatula to gently mix just until combined. Then, use your hands to do a final mix to try and incorporate any flour at the bottom. The batter will be a bit crumbly. Add the strawberries and use your hands to mix them in as best you can without overmixing.
Use floured hands to shape/press the dough into one large or 2 small balls/discs (for large or mini scones). Incorporate any bits of dough at the bottom (if a few strawberries fall to the bottom, you can press them on top later).
Transfer to a floured counter or cutting board. If making mini scones, use your hands to flatten the dough into a disc (two 5-inch discs or one 8-inch disc). You can sprinkle flour on your hands to prevent sticking. Use a knife or bench scraper to cut each round into 8 triangle scones or you can cut them into squares of any size.
Transfer to the baking sheet (if it’s sticking to the counter, use a spatula or bench scraper to help release them) and bake for 20 minutes or until deeply golden brown on the top and bottom. Let cool for at least 20 minutes.
Top with whipped cream and strawberries.