In a medium bowl, combine corn, black beans, red bell peppers, green onions and tomato. In a small bowl, place cumin, sugar, 1/4 t. Kosher salt, and 1/8 t. black pepper. Whisk in vinegar and 1/2 t. canola oil; stir mixture into vegetables; set aside.
In a large bowl, mix together hash brown potatoes, garlic, 2 T. cilantro, yellow onion, taco seasoning, remaining 1 t. Kosher salt and 1/4 t. black pepper. Mix in eggs and flour. In a large non-stick saute pan or skillet, heat canola oil and butter over medium-high heat, using 1 tablespoon of each at a time. Spoon 6 mounds of potato mixture, using 2 generous tablespoons for each into heated oil mixture. Fry several minutes until golden brown and crisp on underside; flip over and fry until golden and crisp.
Drain on paper toweling. Repeat with remaining oil and butter and potato mixture, making 6 more mounds; drain on toweling.
Spoon corn/bean mixture evenly over each potato cake. Divide crumbled goat cheese evenly over cakes and sprinkle with remaining 1 T. chopped cilantro. Place potato cake bruschettas onto a serving platter.