In saucepot, add potatoes and cover with water and pinch of salt. Bring to boil and reduce heat to simmer, cooking for 12 minutes. Drain, transfer to bowl and mash. Set aside.

Heat butter in skillet over medium heat. Add onions and sauté for 10 minutes. Add spinach, pink salt, pepper and vegetable broth and sauté for roughly 7 minutes, stirring occasionally until spinach wilts and excess water evaporates. Stir in garlic and cook until fragrant or 1 minute. Once softened, remove spinach mixture from heat and add to mashed potatoes. Add chives and softened cream cheese, stirring until well combined. Refrigerate to cool completely.

In stand mixer, whisk flour, baking powder and salt.

In small bowl, mix butter, vinegar, water and prepared egg replacer. Pour into flour mixture and combine until dough-like consistency forms. Turn dough out onto floured surface and knead to form into dough shape. Transfer dough to bowl and cover with damp kitchen towel. Set aside for 45 minutes to 1 hour.

To form knishes, roll dough into a large 14x20-1/2-in. rectangle (paper thin). Scoop four even portions, finger-width apart, lengthwise and 3 inches from the edge. Brush bottom piece with water or oat mylk.

Preheat oven to 375 degrees F. Line baking sheet with parchment paper.

Take the bottom part of the dough (the 3-in edge closest to you) and fold it, paper-thin, over the potato and spinach mixture. Roll dough, turning as you roll to tuck in the edges until you get to the end. Carefully stretch remaining dough on top in an even layer.

Using your hand, form a puck shape by slightly flattening and place on the prepared baking sheet. Use fork to create 2-3 pokes on top for air holes.

Bake for 40 minutes or until golden brown. Serve either hot or warm.