Whisk together first 4 ingredients.
Melt butter in a large nonstick skillet over medium heat; add egg mixture, and cook, without stirring, until eggs begin to set on bottom. Sprinkle cream cheese cubes evenly over egg mixture; draw a spatula across bottom of skillet to form large curds.
Cook until eggs are thickened but still moist. (Do not stir constantly.) Remove from heat. Stir in chopped jalapeño pepper before serving.
Sprinkle tortillas evenly with 1 1/2 cups shredded colby-Jack cheese. Top one half of each tortilla evenly with scrambled eggs and sausage. Sprinkle evenly with 1/2 cup shredded colby-Jack cheese. Fold tortillas over filling. Serve with sour cream and salsa.
Note: To lighten, substitute 2 cups egg substitute for eggs and 3 ounces light cream cheese for 3 ounces regular cream cheese. Proceed as directed.