Do I need to place a second license notice on my own code under the Apache License?

Question

I have a project template that I have published to GitHub which is currently licensed under the Apache 2.0 License (I am the sole author/contributor). I want to use this template in another project which is also going to be licensed under the ALv2 and published to GitHub (the template will obviously be modified to fit my needs).

Since I have written this code myself, do I have to place the original copyright notice of my template file in my new project file as well?

To give an example, suppose there was a file in the template CMakeLists.txt:

# CMakeLists.txt - Contains CMake configuration for whole project
# Copyright 2018 Arnav Borborah
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

... Contents ...

Project Name

Now in my new project (the one using the template), I do this:

# NewCMakeLists.txt - Contains CMake configuration for whole project
# Copyright 2018 Arnav Borborah
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

... Contents ...

New Project Name

So, do I have to do anything else (such as putting the original LICENSE file in the root of my project), or do I have to state the modifications I have made with a separate license notice? (This is my own code in both cases.)

Answer 1

If you are the sole author of the code, then there are absolutely no requirements that you need to comply with. The code is completely yours to do with as you see fit. You can even use a completely different license on the second project.

If you accepted contributions from others, then the situation is completely different. In that case, you are bound by the Apache-2.0 license and you need to follow the requirements of that license.
This means in particular that the files that come from the template project need to remain under the Apache license and that you can't remove the existing copyright notice.
There can be reasons to add a second copyright notice for the changes you made while using the template, but there is no need to add a second license text (especially not if it is the same license).