Adjust oven rack to center position and preheat oven to 400°F. Line a baking sheet with foil and place potatoes on top. Brush potatoes all over with oil and bake until pierced easily with a fork, roughly 40 minutes.
Let potatoes stand until cool enough to handle. Cut potatoes in half lengthwise and, using a spoon, scoop out the potato flesh and transfer to a bowl. Reserve the skins for another use, such as potato skins, if desired.

Mix potatoes with 1/4 cup flour along with the salt pepper. Working one at a time, shape potato mixture into 1 1/2-inch cylinders, then flatten into your palm, and place 1 or 2 cheese curds, depending on their size, in the center. Using your fingers, fold the potato around the cheese to re-form the cylinder, making sure the cheese isn't poking through in any spots. Set on a baking sheet and repeat with remaining potato and curds. Set aside.

Combine the water and beef bouillon in a microwave-safe container and microwave until hot, about 1 1/2 minutes; stir to blend. In a saucepan over medium heat, melt butter and mix in remaining 2 tablespoons flour. Cook until lightly browned, then whisk in beef broth. Bring to a boil, stirring occasionally, and reduce to a simmer. Stir in garlic and onion powders and cook, stirring, until gravy thickens, about 3 minutes. Keep warm until ready to serve.

In a deep fryer, Dutch oven, or wok, heat at least 2 inches of oil to 375°F. Working in batches of 4 or 5, add poppers to oil and fry until golden brown, flipping for even browning all over, about 5 minutes. Using a slotted spoon or spider, transfer fried poppers to a paper towel-lined plate. Serve right away with warm gravy.