Preheat your oven to 400°F (200°C). Wash the potatoes thoroughly and pat them dry with a towel. Pierce each potato a few times with a fork so steam can escape while baking.
Place the potatoes on a baking tray and drizzle lightly with olive oil. Bake them for about 40–45 minutes until soft and fork tender. The skins should look slightly crisp while the inside stays fluffy.
Remove the potatoes from the oven and let them cool for a few minutes. Slice them open carefully and fluff the inside with a fork to create room for the filling.
Heat olive oil and butter in a large skillet over medium heat. Add the diced onions and cook until soft and lightly golden. Stir occasionally so they cook evenly without burning.
Add the sliced mushrooms and cook them until they release moisture and turn beautifully browned. Avoid overcrowding the pan because mushrooms brown better with enough space.
Mix in the garlic, paprika, salt, and black pepper. Cook for another minute until the garlic becomes fragrant and blends into the mushrooms perfectly.
Add the fresh spinach to the skillet and stir gently until wilted. The spinach cooks quickly, so avoid overcooking it to maintain its vibrant green color.
Pour in the heavy cream and stir slowly to combine everything. Let the mixture simmer for a few minutes until slightly thickened and creamy.
Add parmesan cheese and nutritional yeast if using. Stir well until the cheese melts completely into the sauce and creates a rich, velvety texture.
Carefully spoon the creamy mushroom spinach mixture into each baked potato. Make sure every potato gets a generous amount of filling for maximum flavor.
Return the stuffed potatoes to the oven for about 5 minutes. This extra baking time helps the filling heat through and slightly crisp on top.
Remove from the oven and garnish with fresh parsley. Serve warm while the filling is creamy and the potatoes are soft and fluffy.