Heat 2 tablespoons of the olive oil in a small skillet over medium-high heat until it shimmers. Add the rinsed, dried capers and fry, stirring now and then, until they pop and turn lightly browned and crisp, 2 to 3 minutes. Lift them out with a slotted spoon and drain on paper towels. In a large bowl, whisk the remaining olive oil with the mustard, honey, vinegar, salt, pepper and lemon juice until smooth and emulsified. Pick off a handful of fennel fronds and set aside, then trim off the stalks. Shave the fennel bulbs thinly on a mandoline and add to the dressing. Add the fried capers and hazelnuts and toss. Transfer to a serving dish, top with fronds, more pepper and a few more hazelnuts, and shave Manchego over the salad with a vegetable peeler.