Step 1: Prepare the Dough
1. Activate Yeast: In a small bowl, combine warm water, sugar, and yeast. Let it sit for about 5-10 minutes until frothy.
2. Mix Ingredients: In a large mixing bowl, combine 3 1/2 cups of flour and salt. Add the melted butter, egg, and the yeast mixture. Mix until a dough forms.
3. Knead Dough: Turn the dough out onto a floured surface and knead for about 5-7 minutes until smooth and elastic. If the dough is too sticky, gradually add more flour.
4. First Rise: Place the dough in a greased bowl, cover it with a clean kitchen towel, and let it rise in a warm place for about 1 hour, or until doubled in size.

Step 2: Prepare the Filling
1. Mix Filling Ingredients: In a medium bowl, combine the softened cream cheese, shredded cheddar cheese, diced jalapeños, garlic powder, onion powder, salt, and pepper. Mix until well combined.

Step 3: Assemble the Rolls
1. Preheat Oven: Preheat your oven to 375°F (190°C) and line a baking sheet with parchment paper.
2. Roll Out Dough: Once the dough has risen, punch it down and turn it out onto a floured surface. Roll it out into a rectangle (about 12×18 inches).
3. Spread Filling: Spread the jalapeño filling evenly over the dough, leaving a small border around the edges.
4. Roll Up: Starting from one long side, tightly roll the dough into a log. Pinch the seam to seal.
5. Cut Rolls: Cut the rolled dough into 12 equal pieces and place them cut-side up on the prepared baking sheet.

Step 4: Bake the Rolls
1. Second Rise: Cover the rolls with a kitchen towel and let them rise for another 30 minutes.
2. Brush with Butter: After the second rise, brush the tops of the rolls with melted butter and sprinkle with breadcrumbs if desired.
3. Bake: Bake in the preheated oven for 20-25 minutes, or until golden brown and cooked through.

Step 5: Serve
1. Cool Slightly: Let the rolls cool for a few minutes before serving. They are best enjoyed warm!