Heat butter and 2 tablespoons olive oil in a medium saucepan over medium until butter is melted. Add shallots, garlic, jalapeño, and cumin seeds; sprinkle with ¼ teaspoon salt and ¼ teaspoon black pepper. Cook, stirring occasionally, until shallots are softened and cumin is fragrant, about 5 minutes. Add wine; cook, stirring often, until nearly evaporated, about 3 minutes. Add broth, and bring to a simmer over medium-high.
Stir cannellini beans and their liquid and drained cranberry beans into broth in saucepan. Bring to a simmer over medium, and cook, gently stirring occasionally, until hot, about 5 minutes. Add spinach, and cook, stirring often, until wilted, about 2 minutes. Stir in lemon juice and lime juice; sprinkle with remaining ½ teaspoon salt and remaining ¼ teaspoon black pepper.
Heat 2 tablespoons olive oil in a large skillet over medium-high. Add 2 bread slices; cook, turning once or twice, until nicely toasted on both sides, 3 to 5 minutes. Place 1 slice in each of 2 bowls. Repeat process with remaining 2 tablespoons olive oil and remaining 2 bread slices. Spoon saucy beans evenly over bread slices. Sprinkle with shredded Parmesan, chives, lemon zest, and lime zest. Serve immediately.
