Mash one-third of the strawberries in a bowl with a potato masher or fork. Stir in sugar. Cut remaining strawberries in quarters (halves for small strawberries) and stir into mashed strawberries. Cover and set aside for at least 30 minutes, or up to 2 hours. Or refrigerate up to 6 hours ahead. Taste and adjust sweetness before serving.
Whisk flour, sugar, baking powder, psyllium, salt, and baking soda together in a mixing bowl. Mix in butter with a pastry blender or fork until lumps are about the size of a pea. Whisk yogurt, oil, and lemon juice together in a bowl. Stir yogurt mixture into flour mixture until thoroughly mixed. Cover and let stand for 30 minutes.
Heat oven to 450° F. Place a rimmed baking sheet inside a second one and line it with parchment paper.
Using a heaping ¼ -cup spring-loaded scoop or a greased ¼ -cup measuring cup, drop 8 scoops of dough close to each other on prepared baking sheet. Sprinkle with sugar. Bake 15 minutes, rotating baking sheet halfway through baking, until bottoms are lightly browned. Transfer to a wire rack and let cool for 30 minutes.
Split each shortcake in half horizontally and place in individual bowls. Using a slotted spoon, place strawberries on top, then dollop with whipped cream. Serve immediately.
Notes
–Adapted from How Can it be Gluten-Free, volume 2 by America’s Test Kitchen.Variations:
Sweeten strawberries with stevia and reduce sugar.
Gluten-Free Biscuits: Reduce sugar to 1 teaspoon. Omit sugar on top.