Please have the following steps closely followed to create a custom richtext control inside your page layout and have it display with chrome.
Create a custom content type
a) Go to site settings > Galleries > Site Content Types > Create > followed by the screenshot as mentioned below
Save the content type and you will be redirected to the newly created content type modification page. Scroll below and you will the see option "Add from new site column". Click on that and create a custom site column . Please follow the screenshot below :-
Then create your page layout (site settings > galleries> masterpage and page layouts) using the newly created custom content type. Refer to the screenshot below
Now edit this page layout in SharePoint designer and drag the publishing column from the toolbox > SharePoint Controls > Content Fields as shown in the below screenshot.
Once dragged in the required region of the page (generally inside a div or a table) you will a markup generated by SharePoint something like this :-
<PublishingWebControls:RichHtmlField FieldName="6946f02c-c941-452e-be99-14126eb266ef" runat="server"></PublishingWebControls:RichHtmlField>
Now modify this to give it a field name so that it appears during the edit page mode.
<PublishingWebControls:RichHtmlField InputFieldLabel="centercontentbox" FieldName="6946f02c-c941-452e-be99-14126eb266ef" runat="server"></PublishingWebControls:RichHtmlField>
Save the page layout.
Pages Document Library (assuming you have publishing feature activated)
Go to the document library where your landing page or the page where you want the rich text content to come. This is generally Pages library or Site Pages Library. Go to library settings and add from existing content type to this library as shown below
Final step involves in creating a page inside this library using this content type.
Once you have selected this content type , just selected associate page layout for this page as "mypagelayout.aspx".
Now you will have the richtextbox control come up with a name "Centercontentbox" with chrome surrounding it. All it needs is no messed up RTE or editmode css included within the masterpage.