Onion Jam and Goat Cheese Rugelach | The Fancy Pants Kitchen

Ingredients

• 1 cup unsalted butter (8 ounces), cut into pieces, at room temperature
• 1 (8-ounce) package cream cheese, cut into pieces, at room temperature
• 1/2 tsp Kosher salt
• 2 cups all-purpose flour (about 8 & 1/2 ounces), plus more for work surface
• 2 tbsp extra-virgin olive oil
• 1 & 3/4 pounds yellow onions, thinly sliced (about 7 cups)
• 1 & 1/2 tsp Kosher salt
• 3/4 cup (6 ounces) dry white wine
• 1/4 cup granulated sugar
• 1 & 1/2 tbsp balsamic vinegar
• 1 tsp ground sumac
• 3/4 tsp ground coriander
• 1/4 tsp black pepper
• 4 ounces goat cheese, crumbled (about 1 cup), divided
• 1 large egg, beaten
• Flaky sea salt or smoked flaky sea salt