Preheat your oven to 425°F and line a baking sheet with parchment paper. This ensures the potatoes do not stick to the baking surface and helps with even cooking.
Boil the baby potatoes in well-salted water for 7-8 minutes until they are just fork-tender. Be careful not to over-boil to maintain their structure. Once boiled, drain them and allow them to cool slightly.
Pat the potatoes dry with a clean kitchen towel. Then, gently smash each potato with a glass until it is flattened but still holds its shape. Brush the smashed potatoes with 2 tbsp olive oil and season with salt and pepper.
Roast the potatoes in the preheated oven for 45-60 minutes, turning them halfway through, until they are golden and crispy. Keep a close eye on them towards the end for the best results.
While the potatoes roast, prepare the dressing. In a mixing bowl, whisk together the remaining 1 tbsp olive oil, Greek yogurt, mayonnaise, Dijon mustard, lemon juice, minced garlic, and chopped parsley until smooth and well-combined.
Stir in the finely chopped pickle and shallot, and taste the dressing. Adjust the seasoning with salt and pepper as needed. Place the dressing in the refrigerator to chill and allow the flavors to meld.
Once the potatoes are done, let them cool for about 5 minutes. Set aside any extra crispy bits that may have formed and toss the warm potatoes with the herbed yogurt dressing until they are well coated.
To serve, garnish with scallions and crispy potato bits. For the most delightful experience, serve the salad warm.